Abortion-breast cancer hypothesis
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2008-07-11T01:38:39Z
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{{Abortion debate (sidebar)}}
The '''abortion-breast cancer (ABC) hypothesis''' (supporters call it the abortion-breast cancer link) posits that induced [[abortion]] increases the risk of developing [[breast cancer]];<ref name="RUSSO_505">{{cite journal |author=Russo J, Russo I |title=Susceptibility of the mammary gland to carcinogenesis. II. Pregnancy interruption as a risk factor in tumor incidence |journal=Am J Pathol |volume=100 |issue=2 |pages=505–506 |year=1980 |pmid=6773421}} "In contrast, abortion is associated with increased risk of carcinomas of the breast. The explanation for these epidemiologic findings is not known, but the parallelism between the DMBA-induced rat mammary carcinoma model and the human situation is striking. [...] Abortion would interrupt this process, leaving in the gland undifferentiated structures like those observed in the rat mammary gland, which could render the gland again susceptible to carcinogenesis."</ref> it is a controversial subject and the current [[scientific consensus]] has concluded there is no significant association between first-trimester abortion and breast cancer risk.<ref name="WHO">{{cite web |url=http://www.who.int/mediacentre/factsheets/fs240/en/index.html |title=WHO | Induced abortion does not increase breast cancer risk |accessdate=2007-12-24 |format= |work=who.int}}</ref><ref name="oversight">{{cite web |url=http://oversight.house.gov/features/politics_and_science/example_breast_cancer.htm |title=Politics & Science - Investigating the State of Science Under the Bush Administration |accessdate=2008-04-14 |format=HTML |work=oversight.house.gov}}</ref><ref name="JASEN"/>
In early [[pregnancy]], levels of [[estrogen]] increase, leading to [[breast]] growth in preparation for [[lactation]]. The hypothesis proposes that if this process is interrupted by an abortion{{ndash}} before full maturity in the third [[trimester]]{{ndash}} then more relatively vulnerable immature cells could be left than there were prior to the pregnancy, resulting in a greater potential risk of breast cancer. The hypothesis mechanism was first proposed and explored in [[rat]] studies conducted in the 1980s.<ref name="RUSSO">{{cite journal |author=Russo J, Russo I |title=Susceptibility of the mammary gland to carcinogenesis. II. Pregnancy interruption as a risk factor in tumor incidence |journal=Am J Pathol |volume=100 |issue=2 |pages=497–512 |year=1980 |pmid=6773421}}</ref><ref name="RUSSO2">{{cite journal |author=Russo J, Tay L, Russo I |title=Differentiation of the mammary gland and susceptibility to carcinogenesis |journal=Breast Cancer Res Treat |volume=2 |issue=1 |pages=5–73 |year=1982 |pmid=6216933 |doi=10.1007/BF01805718}}</ref><ref name="RUSSO3">{{cite journal |author=Russo J, Russo I |title=Biological and molecular bases of mammary carcinogenesis |journal=Lab Invest |volume=57 |issue=2 |pages=112–37 |year=1987 |pmid=3302534}}</ref>
The [[American Cancer Society]] concludes that presently the evidence does not support a causal abortion-breast cancer association,<ref name="ACS_ABC">{{cite web |url=http://www.cancer.org/docroot/CRI/content/CRI_2_6x_Can_Having_an_Abortion_Cause_or_Contribute_to_Breast_Cancer.asp |title=ACS :: Can Having an Abortion Cause or Contribute to Breast Cancer? |accessdate=2008-03-31 |format= |work=cancer.org}}</ref> yet pro-life activists like Dr. [[Joel Brind]], Dr. Angela Lanfranchi and Karen Malec continue to champion a causal link.<ref name="JASEN"/> In the past, pro-life advocates have sought legal action regarding disclosure of the abortion-breast cancer issue. This brought short-term legal and political intervention culminating with the Bush Administration changing the [[National Cancer Institute]] (NCI) fact sheet from concluding no link to a more ambiguous assessment.<ref name="HOUSE">{{cite web |url=http://democrats.reform.house.gov/features/politics_and_science/example_breast_cancer.htm |title=Politics & Science - Investigating the State of Science Under the Bush Administration |accessdate=2007-11-04 |format= |work=democrats.reform.house.gov}}</ref> In February 2003, the NCI responded by conducting a workshop with over 100 experts on the issue, which determined from selected evidence that it was well-established "abortion is not associated with an increase in breast cancer risk."<ref name="NCI">{{cite web |url=http://www.cancer.gov/cancerinfo/ere-workshop-report |title=Summary Report: Early Reproductive Events Workshop - National Cancer Institute |accessdate=2007-11-04 |format= |work=cancer.gov}}</ref>
Though the scientific community is largely skeptical of the hypothesis and has been rejected by some;<ref name="HOUSE"/><ref name="NCI"/> the ongoing promotion of an abortion-breast cancer "link" by [[pro-life]] advocates and medical associations is seen by others as merely a part of the current pro-life "woman-centered" strategy against abortion.<ref name="ABC_medical">{{cite web |url=http://www.abortionbreastcancer.com/medicalgroups/index.htm |title=Medical Groups Recognizing Link |accessdate=2008-04-14 |format= |work=abortionbreastcancer.com}}</ref><ref name="ARTHUR">{{cite web |url=http://www.prochoiceactionnetwork-canada.org/articles/abclink.shtml |title=THE PRO-CHOICE ACTION NETWORK |accessdate=2007-11-04 |format= |work=prochoiceactionnetwork-canada.org}}</ref><ref name="Mooney">{{cite web |url=http://www.washingtonmonthly.com/features/2004/0410.mooney.html |title=Research and Destroy |accessdate=2008-04-14 |format= |work=washingtonmonthly.com |author=Chris Mooney |year=2004}}</ref> Pro-life groups maintain they are providing legally necessary [[informed consent]];<ref name="deveber">{{cite web |url=http://www.deveber.org/text/whealth.html#eighteen |title=Women's Health after Abortion |accessdate=2008-04-14 |format= |work=deveber.org}}</ref> a concern shared by conservative Congressman Dr. [[Dave Weldon]].<ref name="Weldon">{{cite web |url=http://www.abortionbreastcancer.com/weldon_letter.htm |title=Weldon Letter |accessdate=2007-11-04 |format= |work=abortionbreastcancer.com}}</ref> While early research indicated a correlation between breast cancer and abortion;<ref name="DALING2">{{cite journal |author=Daling JR, Brinton LA, Voigt LF, ''et al'' |title=Risk of breast cancer among white women following induced abortion |journal=Am. J. Epidemiol. |volume=144 |issue=4 |pages=373–80 |year=1996 |pmid=8712194 |doi=}}</ref><ref name="HOWE">{{cite journal |author=Howe H, Senie R, Bzduch H, Herzfeld P |title=Early abortion and breast cancer risk among women under age 40 | journal = Int J Epidemiol | volume = 18 | issue = 2 |pages=300–4 |year=1989 | pmid = 2767842 | doi = 10.1093/ije/18.2.300}}</ref> the current scientific consensus has solidified with the publication of large [[prospective study|prospective]] [[cohort study|cohort studies]] which find no clear association between abortion and breast cancer.<ref name="MELBYE">{{cite journal |author=Melbye M, Wohlfahrt J, Olsen J, Frisch M, Westergaard T, Helweg-Larsen K, Andersen P |title=Induced abortion and the risk of breast cancer |journal=N Engl J Med |volume=336 |issue=2 |pages=81–5 |year=1997 |pmid=8988884 |doi=10.1056/NEJM199701093360201}}</ref><ref name="Michels">{{cite journal |author=Michels KB, Xue F, Colditz GA, Willett WC |title=Induced and spontaneous abortion and incidence of breast cancer among young women: a prospective cohort study |journal=Arch. Intern. Med. |volume=167 |issue=8 |pages=814–20 |year=2007 |pmid=17452545 |doi=10.1001/archinte.167.8.814}}</ref> These studies along with all relevant research strive to remove from their results the many [[Abortion-breast cancer hypothesis#Confounding factors|confounding factors]], such as delayed child bearing (parity), which affect breast cancer risk apart from abortion. The abortion-breast cancer hypothesis continues to incite mostly political and some scientific debate.<ref name="JASEN">{{cite journal |author=Jasen P |title=[http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1251638 Breast cancer and the politics of abortion in the United States] |journal=Med Hist |volume=49 |issue=4 |pages=423–44 |year=2005 |pmid=16562329}}</ref>
==Proposed mechanism==
[[Image:Breast anatomy drawing.png|thumb|200px|Lobules pointed to by number 3,<br/> ducts are number 6.]]
While research has shown the protective benefits of full-term pregnancy and lactation in reducing the risk of breast cancer, these benefits are only fully realized in the third trimester when differentiation of new breast growth takes place. The abortion-breast cancer hypothesis posits that if a pregnancy is aborted prior to differentiation it could have an adverse effect by creating and leaving behind more immature cells to be exposed to carcinogens and hormones over time.
Breast tissue contains many [[Lobe (anatomy)|lobe]]s (segments) and these contain lobules which are groups of breast cells. There are four types of lobules:
*Type 1 has 11 [[Duct (anatomy)|ductules]] (immature)
*Type 2 has 47 ductules (immature)
*Type 3 has 80 ductules (mature, fewer [[hormone receptor]]s)
*Type 4 are fully matured ([[cancer]] resistant) and contain [[breast milk]]
During early pregnancy, type 1 lobules quickly become type 2 lobules because of changes in estrogen and progesterone levels. Maturing into type 3 and then reaching full [[cellular differentiation|differentiation]] as type 4 lobules requires an increase of [[human placental lactogen]] (hPL) which occurs in the last few months of pregnancy. According to the abortion-breast cancer hypothesis, if an abortion were to interrupt this sequence then it could leave a higher ratio of type 2 lobules than existed prior to the pregnancy.<ref name="bcp">{{cite web |url=http://bcpinstitute.org/reproductive.htm#R2 |title=Reproductive Breast Cancer Risks Brochure |accessdate=2007-10-20 |format= |work=}}</ref> Russo and Russo have shown that mature breast cells have more time for DNA [[DNA repair|repair]] with longer [[cell cycle]]s<ref name="ANNIE"/> which would account for the reduced risk of parturition against the baseline risk for women who have never conceived and those who have conceived and terminated their pregnancies.<ref name="RUSSO"/>
Later on, Russo ''et al.'' found that placental [[human chorionic gonadotropin]] (hCG) induces the synthesis of [[inhibin]] by the mammary epithelium.<ref>{{cite journal |author=Alvarado MV, Alvarado NE, Russo J, Russo IH |title=Human chorionic gonadotropin inhibits proliferation and induces expression of inhibin in human breast epithelial cells in vitro |journal=In Vitro Cell. Dev. Biol. Anim. |volume=30A |issue=1 |pages=4–8 |year=1994 |pmid=8193772 |doi=10.1007/BF02631407}}</ref><ref>{{cite journal |author=Russo IH, Koszalka M, Russo J |title=Effect of human chorionic gonadotropin on mammary gland differentiation and carcinogenesis |journal=Carcinogenesis |volume=11 |issue=10 |pages=1849–55 |year=1990 |pmid=2119909 |doi=10.1093/carcin/11.10.1849}}</ref> Bernstein ''et al.'' independently observed
a reduced breast cancer risk when women were injected with hCG for weight loss or [[Assisted reproductive technology|infertility treatment]].<ref>{{cite journal |author=Bernstein L, Hanisch R, Sullivan-Halley J, Ross RK |title=Treatment with human chorionic gonadotropin and risk of breast cancer |journal=Cancer Epidemiol. Biomarkers Prev. |volume=4 |issue=5 |pages=437–40 |year=1995 |pmid=7549796 |doi=}}</ref> Contrary to the ABC hypothesis, Michaels ''et al.'' hypothesize since hCG plays a role in cellular differentiation and may activate [[apoptosis]], as levels of hCG increase early on in human pregnancy, "an incomplete pregnancy of short duration might impart the benefits of a full-term pregnancy and thus reduce the risk of breast cancer."<ref name="Michels"/>
==Proponents==
[[Joel Brind|Dr. Joel Brind]] is a professor of biology and [[endocrinology]] at [[Baruch College]]; and is the primary advocate of an ABC link. While Brind is pro-life and his focus is on the ABC link, he has published papers in respected journals on other human hormone topics.<ref>{{cite web|url=http://www.baruch.cuny.edu/wsas/departments/natural_science/faculty/brind.html|title=Joel Brind, Department of Natural Sciences|publisher=Baruch College|accessdate=2008-06-29}}</ref> He has fought against the legalization of [[RU-486]] testifying at a federal hearing that "thousands upon thousands" of women would develop breast cancer as a result of using the drug.<ref name="CWA_RU">{{cite web |url=http://www.cwfa.org/familyvoice/2000-11/14-19.asp |title=Concerned Women for America - Family Voice |format= |work= |accessdate=}}</ref>
In 1996, Brind published a meta-analysis which was immediately criticized in a ''Journal of the National Cancer Institute'' editorial for concluding [[Abortion-breast cancer hypothesis#Response bias|response bias]] was unlikely to have affected their results, "dismissal of the study's limitations, and their blurring of association with causation."<ref name="WEED">{{cite journal |author=Weed DL, Kramer BS |title=Induced abortion, bias, and breast cancer: why epidemiology hasn't reached its limit |journal=J. Natl. Cancer Inst. |volume=88 |issue=23 |pages=1698–700 |year=1996 |pmid=8943995 |doi=10.1093/jnci/88.23.1698}}</ref> However, the [[Royal College of Obstetricians and Gynaecologists]] noted in 2000 that "Brind's paper had no methodological shortcomings and could not be disregarded."<ref name="rcog_2000">{{cite web |url=http://www.rcog.org.uk/resources/Public/pdf/induced_abortionfull.pdf |title=The Care of Women Requesting Induced Abortion |page=43 |format=PDF |work= |accessdate=2008-06-29}}</ref> After his study failed to convince the scientific community of a causal relationship, Brind co-founded the Breast Cancer Prevention Institute (BCPI) in 1999 with Dr. Angela Lanfranchi, a surgeon and pro-life advocate. In 2003, Brind was invited to the [[Abortion-breast cancer hypothesis#National Cancer Institute|NCI workshop]], where he was the only one to formally dissent.
Karen Malec, a former teacher and pro-life activist, started the Coalition on Abortion-Breast (CAB) in 1999 with help from [[Concerned Women for America]],<ref name="JASEN"/> a national organization which lobbies for legislation recognizing an abortion-breast cancer link.
==Background==
The first study involving statistics on abortion and breast cancer was a broad study in 1957,<ref name="JASEN"/> which examined common cancers in [[Japan]]. The researchers were cautious about drawing any conclusions from their unreliable methodologies. During the 1960s several studies by [[Brian MacMahon]] et al. in Europe and Asia touched on a correlation between abortion and breast cancer. Their results were summarized by the ''Journal of the National Cancer Institute'' in 1973 which inaccurately<ref name="JASEN"/> concluded that "where a relationship was observed, abortion was associated with increased, not decreased, risk."<ref>{{cite journal |author=B MacMahon, P Cole, and J Brown |title=Etiology of human breast cancer: a review | journal = J. Nat. Cancer Inst. | volume = 50 | issue = 21–42 |pages=22 |year=1973 | pmid = 4571238}}</ref> Research relevant to the current ABC discussion focuses on more recent large [[Cohort study|cohort studies]], a few [[meta-analysis|meta-analyses]], many [[case-control]] studies and several early experiments with [[Rat#Rats as subjects of scientific research|rats]].
====Rats====
Drs. Russo & Russo from the [[Fox Chase Cancer Center]] in [[Philadelphia]] conducted a study in 1980 which examined the proposed correlation between abortion and breast cancer. Russo and Russo examined the effects of the carcinogen 7,12-dimethylbenz(a)anthracene (DMBA) on the DNA labeling index (DNA-LI) in terminal end buds (TEBs), terminal ducts (TDs) and alveolar buds (ABs) of Sprague-Dawley rats in various stages of reproductive development. Russo and Russo found that rats who had interrupted pregnancies had no noticeable increase in risk for cancer.<ref name="RUSSO"/> However, they did find that pregnancy and lactation provided a protective measure against various forms of benign lesions, like hyperplastic alveolar nodules and cysts. While results did suggest that rats who had interrupted pregnancies might be subject to "similar or even higher incidence of benign lesions" than virgin rats, there was no evidence to suggest that abortion would result in a higher incidence of carcinogenesis. A more thorough examination of the phenomenon was conducted in 1982, which confirmed the results.<ref name="RUSSO2"/> A later study in 1987 further explained their previous findings.<ref name="RUSSO3"/> After differentiation of the [[mammary gland]] resulting from a full-term pregnancy of the rat, the rate of cell division decreases and the cell cycle length increases, allowing more time for [[DNA]] [[DNA repair|repair]].<ref name="RUSSO3"/><ref name="ANNIE">{{cite web |url=http://www.annieappleseedproject.org/addietrisofb.html |title=Adolescent Diet & Risk of Bca |accessdate=2007-11-04 |format= |work=annieappleseedproject.org}}</ref>
Despite the fact that the Russos' studies found similar risk rates between virgin and pregnancy interrupted rats, their research would be used to support the contention that abortion created a greater risk of breast cancer for the next twenty years.<ref>{{cite journal |last=Jasen |first=Patricia |year=2005 |month=October |title=Breast Cancer and the Politics of Abortion in the United States |journal=Medical History |volume=49 |issue=4 |pages=423–444 |url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=16562329#fn16 |accessdate= 2007-11-16 |quote=Their study supported the theory that structural changes in breast tissue are responsible for the lasting, protective effect of full-term pregnancy. They observed that abortion left the rats highly susceptible to developing cancer, but that the aborted rats “were ''at the same risk'' as virgin animals treated with the carcinogen” (italics mine). Over the next two decades, however, their findings would be cited repeatedly as evidence that pregnancy begins a process of breast change which, when stopped by abortion, put female rats (and thus humans) at greater risk of cancer than those who had never been pregnant. |pmid=16562329}}</ref> In a [[Discover Magazine|Discover]] article sidebar entitled ''Humans Are Not Rats'', Dr. Gil Mor, the director of reproductive immunology at the [[Yale University|Yale University School of Medicine]], disagrees with Dr. Brind on the importance of the rat studies findings. Dr. Mor emphasizes that rat studies are ideal for understanding basic processes but because rats have neither breasts nor breast cancer, people like Dr. Brind are on "wobbly" terrain.<ref>{{cite web |last=Yeoman|first=Barry |url=http://www.barryyeoman.com/articles/hatedabortion.html |title=Scientist Who Hated Abortion |accessdate=2007-11-04 |format= |work=Discover}}</ref>
==Epidemiological studies==
The majority of the results in [[epidemiology]] are calculated as a [[relative risk]], where 1.0 is no risk; results above, like 1.21, is a 21% increased risk and results below, such as 0.8 is a 20% decreased risk. Relative risks are not necessarily significant. To help assess this a relative risk is followed by a [[confidence interval]] in brackets that shows the likelihood (with 95% confidence) that the relative risk is of significance. Any relative risk with a confidence interval that does not include a value of 1 could be considered significant. For example, the confidence intervals (0.3 - 0.9) and (1.5 - 7.8) are statistically significant, whereas the confidence intervals (0.89 - 7.34) or (0.5 - 1.1) are not.<ref>{{cite web |url=http://www.health.state.pa.us/hpa/stats/techassist/risknotion.htm |title=Tools of the Trade: The Notion of Risk |accessdate=2007-11-27 |format= |work= }}</ref> With more data the confidence interval becomes smaller; making it an indicator of the result's statistical reliability.
When a relative risk result actually becomes significant is a difficult and contentious issue.<ref>{{cite web |url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1251638#id2609843 |title=Breast Cancer and the Politics of Abortion in the United States |accessdate=2007-12-09 |format= |work=}}</ref> As a small result of 1.41 (1.1 - 1.6) even a significant confidence interval (outside 1.0) may be inaccurate because of [[response bias]], incomplete data, missed [[Abortion-breast_cancer_hypothesis#Confounding_factors|confounding factor]]s, imprecise controls or statistical analysis. If these possible flaws are accounted for they could change the result and/or the confidence interval impacting its statistical significance.
The number of (X/Y ABC cases/controls) gives X as women in the study who have had abortion(s) (induced and/or spontaneous) with breast cancer and Y is women with breast cancer and no abortion history. This dataset is used when calculating the relative risk and provides a way to compare the size of one study to another.
===Confounding factors===
There are many [[Lurking variable|confounding factor]]s for breast cancer. [[Genetics]] is a major factor that affects not only a woman's initial breast cancer risk<ref>{{cite web |url=http://www.breastcancer.org/genetics_cancer_risk.html |title=Cancer Risk and Abnormal Breast Cancer Genes |accessdate=2007-11-04 |format= |work=}}</ref> but also her [[Estrogen receptor#Cancer|hormonal sensitivity]], which in turn affects her susceptibility to a long list of socioeconomic and environmental factors. As [[Western world|Western society]] has modernized [[natural environment|environmental]] [[carcinogens]], delayed child rearing, less [[breastfeeding]], [[hormone replacement therapy]] (HRT), [[hormonal contraception]], early [[menarche]] and [[obesity]] have increased.
If unaccounted for these factors could obscure any individual variable. Scientific studies remove them using [[case-control]] methodology{{ndash}} a woman who has had an abortion (case) is matched with a very similar woman with no abortion history (control){{ndash}} if this was not done a study could get a [[Type I and type II errors|false positive or negative]] result because of another factor. Examining the ABC issue is all the more difficult because the number of women with an induced abortion history has increased along with other factors in recent decades.<ref name="GUTTMACHER"/> [[Premature birth]] adds further complications since uncorroborated studies have indicated it is associated with a history of induced abortion<ref>{{cite journal |author=Moreau C, Kaminski M, Ancel PY, ''et al'' |title=Previous induced abortions and the risk of very preterm delivery: results of the EPIPAGE study |journal=BJOG : an international journal of obstetrics and gynaecology |volume=112 |issue=4 |pages=430–7 |year=2005 |pmid=15777440 |doi=10.1111/j.1471-0528.2004.00478.x}}</ref> and higher breast cancer risk.<ref name="MELBYE2"/> One of the most significant controllable factors for breast cancer is parity, or the number of children a women has given birth to. With each full-term pregnancy (particularly the first) the breasts undergo growth and differentiation (in the third trimester); consequently, having no children can increase breast cancer risk.<ref name="ACS">{{cite web |url=http://www.cancer.org/docroot/CRI/content/CRI_2_4_2X_What_are_the_risk_factors_for_breast_cancer_5.asp |title=ACS :: What Are the Risk Factors for Breast Cancer? |accessdate=2007-11-04 |format= |work=cancer.org}}</ref>
All of these confounding factors have an effect, directly or indirectly, on hormones which impact breast cancer risk, but they do not significantly affect the results of ABC studies that are properly conducted and take these factors into account with [[case-control]] matching. Hormones being a key factor for cancer risk is well established. Steroidal [[estrogen]] was added to the U.S. federal [[carcinogen]] list in December 2002. The [[American Cancer Society]] (ACS)<ref>{{cite web |url=http://www.cancer.org/downloads/STT/BrCaFF2001.pdf |title=Breast Cancer Facts & Figures 2001-2002 |accessdate=2007-11-04 |format= |work=}}</ref> and the [[National Cancer Institute]] (NCI)<ref>{{cite web |url=http://www.cancer.gov/cancertopics/understandingcancer/estrogenreceptors/Slide7 |title=Estrogen Receptors/SERMs - National Cancer Institute |accessdate=2007-11-04 |format= |work=}}</ref> note reproductive hormones can elevate breast cancer risk.<ref>{{cite web |url=http://www.sciencedaily.com/releases/2002/12/021213063325.htm |title=New Federal Report On Carcinogens Lists Estrogen Therapy, Ultraviolet, Wood Dust |accessdate=2007-11-04 |format= |work=}}</ref> In particular a [[Women's Health Initiative]] [[hormone replacement therapy]] study was cut short from an elevated breast cancer and [[heart]] risk using estrogen with [[progestin]].<ref>{{cite web |url=http://jama.ama-assn.org/cgi/content/abstract/289/24/3243 |title=JAMA -- Abstract: Influence of Estrogen Plus Progestin on Breast Cancer and Mammography in Healthy Postmenopausal Women: The Women's Health Initiative Randomized Trial, June 25, 2003, Chlebowski et al. 289 (24): 3243 |accessdate=2007-11-04 |format= |work=}}</ref>
The controversial nature of [[abortion]] may introduce [[response bias]] into interview studies, especially for studies done in decades past when abortion was less accepted;<ref name="WEED"/> however, the significance of bias has yet to be confirmed. In the late 20th century there was some concern of an increase of breast cancer [[Incidence (epidemiology)|incidence]]. This was found to be partly due to longer lifespans, and the development of better detection methods capable of finding breast cancer earlier.<ref>{{cite journal |author=Feuer EJ, Wun LM, Boring CC, Flanders WD, Timmel MJ, Tong T |title=The lifetime risk of developing breast cancer |journal=J. Natl. Cancer Inst. |volume=85 |issue=11 |pages=892–7 |year=1993 |pmid=8492317 |doi=10.1093/jnci/85.11.892}}</ref>
===Cohorts===
====Howe====
The 1989 study by Dr. Holly Howe ''et al.'' at the [[New York]] State Department of Health examined young women with breast cancer in upstate New York (100/63 ABC cases/controls).<ref name="HOWE"/> The results indicated a increased 1.9 (1.2 - 3.0) relative risk for induced abortion and 1.5 (0.7 - 3.7) for spontaneous abortion. Although the study had 1451 breast cancer cases the number of individuals with an abortion history was low; consequently the confidence interval is quite large.
The authors believed that the study was inconclusive as fertility patterns were changing dramatically as a result of legal abortion and increased use of contraceptives. Further they did not have a complete reproductive history of younger women who may still have children affecting the results going forward, but Howe ''et al.'' concluded it raised new questions for continuing research as women's recorded contraceptive histories grew. Dr. Newcomb and Michels point out it examined only very young women and did not account for some confounding factors such as family history of breast cancer.<ref>{{cite web |url=http://www.womensenews.org/article.cfm/dyn/aid/818/context/cover/ |title=Judge to Rule on Abortion, Breast Cancer Link |accessdate=2007-11-04 |format= |work=womensenews.org}}</ref>
====Lindefors-Harris====
Another cohort study by Dr. Lindefors-Harris ''et al.'' (1989) was done looking at 49,000 women who had received abortions before the age of 30 in Sweden (65 ABC cases – compared with estimate of occurrence in the general population).<ref name="LH1989">{{cite journal |author=Harris BM, Eklund G, Meirik O, Rutqvist LE, Wiklund K |title=Risk of cancer of the breast after legal abortion during first trimester: a Swedish register study |journal=BMJ |volume=299 |issue=6713 |pages=1430–2 |year=1989 |pmid=2514825 |doi=}}</ref> The relative risk for women who'd given birth previous to the abortion was 0.58 (0.38 - 0.84), whereas women with no births had an relative risk of 1.09 (0.71 - 1.56). The confidence intervals did not establish statistically significant associations between breast cancer and different stages of reproduction, including abortion. Overall, the relative risk was 0.77 (0.58 - 0.99), making for a 23% reduced risk in comparison to "contemporary Swedish population with due consideration to age."<ref name="LH1989"/>
The study was funded by [[Family Health International]],<ref name="LH1989"/> a pro-choice [[Non-governmental organization|NGO]] and although the study started with 49,000 women there were fewer than 5,000 still in the study after 11 years.<ref name="Kahlenborn">{{cite web |url=http://lifeissues.net/writers/kah/kah_08chap6cancabor.txt |title=CHAPTER 6: BREAST CANCER AND ABORTION|accessdate=2008-01-23 |format= |work=lifeissues.net |author=Chris Kahlenborn}}</ref> Lindefors-Harris made no adjustments for family history of breast cancer and the pill,<ref name="LH1989"/> and provides no explanation for a lack of a control group or why the study was limited to women with an abortion before 30 years of age. Brind contends correcting for either of these removes the 23% "protective" effect; and that the study did not account for the difference of nulliparous women in the cohort 41% in comparison to 49% in the general population.<ref name="BRIND_LH">{{cite web |url=http://www.lifeissues.net/writers/air/air_vol5no3_1993.html |title=lifeissues.net | Induced Abortion as an Independent Risk Factor for Breast Cancer |accessdate=2008-01-23 |format= |work=lifeissues.net |author=Joel Brind}}</ref> Possibly making the protective result about parity (childbearing) rather than abortion.
====Melbye====
A large, highly regarded ABC study was published by Dr. Melbye ''et al.'' (1997) of the Statens Serum Institute in [[Copenhagen]], which had 1.5 million [[Denmark|Danish]] women in the study's database (1,338 ABC cases, no controls used).<ref name="MELBYE"/><ref name="NYT_Brody">{{cite web |url=http://query.nytimes.com/gst/fullpage.html?res=9E03E0DD1F39F93AA35752C0A961958260&sec=health&spon=&pagewanted=1 |title=Big Study Finds No Link In Abortion and Cancer - New York Times |format= |work=New York Times |author=Jane E. Brody |date=January 9, 1997 |accessdate=2008-07-03}}</ref> Of those women, 280,965 of them had induced abortions recorded in the computerized registry, which was started in 1973 when having an induced abortion through 12 weeks was legal in Denmark. The relative risk after statistical adjustment came to 1.00 (0.94 - 1.06); meaning there was zero percent increase or decrease in breast cancer risk. This led to the conclusion that "induced abortions have no overall effect on the risk of breast cancer." The Melbye study's conclusions have been supported by the majority of cancer and gynecological organizations, such as NCI, ACOG, ACS, RCOG and [[Planned Parenthood]], who use it as evidence when they state that the best scientific evidence does not support an ABC link.<ref name="HOUSE"/><ref name="PP">{{cite web |url=http://www.plannedparenthood.org/issues-action/abortion/state-abortion-restrictions/reports/anti-choice-claims-about-abortion-breast-cancer-5095.htm |title=Planned Parenthood - Anti-Choice Claims About Abortion and Breast Cancer |accessdate=2007-11-04 |format= |work=plannedparenthood.org}}</ref>
Drs. Brind and Chinchilli had concerns about the Melbye study database as women in the study were born from 1935 to 1978, but the computerized registry of induced abortions only started in 1973.<ref name="BRINDLET">{{cite journal |author=Brind J, Chinchilli VM |title=Induced abortion and the risk of breast cancer |journal=N. Engl. J. Med. |volume=336 |issue=25 |pages=1834; author reply 1835 |year=1997 |pmid=9190496 |doi=10.1056/NEJM199706193362514}}</ref> Dr. Melbye ''et al.'' responded that if the misclassified older women had their risk underestimated, it would be expected that the younger groups would have a higher risk. The statistically adjusted data indicated this was not the case.
However, the statistical adjustments made were another concern of Dr. Brind who argues that the Melbye study accidentally adjusted out induced abortion from the overall results. Instead of case-control matching, Dr. Melbye ''el al.'' decided to manually remove the many confounding factors that increased over time (eg. smoking, late child bearing, etc.) and were raising breast cancer risk for younger women relative to older women (birth-cohorts). Dr. Brind believes finding exactly zero ABC risk was a consequence and red flag indicating ABC risk was removed along with the confounding factors.<ref name="BRINDLET"/> Dr. Melbye ''et al.'' found the point to be self-contradictory, considering Dr. Brind wanted birth-cohort matching, then argued against "taking birth-cohort differences into account."<ref name="BRINDLET"/> Dr. Brind has stated that he is against the use of just statistical adjustment and that standard [[case-control]] matching may more accurately account for birth-cohort differences.<ref>{{cite web |url=http://abortionbreastcancer.com/article_two.htm |title=ABC in the courts |accessdate=2008-03-21 |format= |work=abortionbreastcancer.com |author=Joel Brind}}</ref>
Another letter to the editor from Drs. Senghas and Dolan questioned why a statistically significant result for induced abortions done after 18 weeks gestation was not specifically addressed in the results section of the Melbye study abstract.<ref name="LETTERS">{{cite journal |author=Senghas R, Dolan M |title=Induced abortion and the risk of breast cancer | journal = N Engl J Med | volume = 336 | issue = 25 |pages=1834; author reply 1835 |year=1997 | pmid = 9190497 | doi = 10.1056/NEJM199706193362514}}</ref> Melbye ''et al.'' explained even though they found the result "interesting and in line with the hypothesis of Russo and Russo, the small number of cases of cancer in women in this category of gestational age prompted us not to overstate the finding."<ref name="LETTERS"/><ref name="RUSSO"/> The first section of Table 1 in the Melbye study:<ref name="MELBYE"/>
{| class="wikitable" border="1" cellpadding="2"
!Week of gestation
!No. of Cancers
!Person-Years
!Relative Risk (95% CI) *
!Multivariate Relative Risk (95% CI) †
|- align="center"
|<7
|36
|82 000
|0.81 (0.58-1.13)
|0.81 (0.58-1.13)
|- align="center"
|7-8
|526
|1 012 000
|1.01 (0.89-1.14)
|1.01 (0.89-1.14)
|- align="center"
|9-10‡
|534
|1 118 000
|1
|1
|- align="center"
|11-12
|205
|422 000
|1.12 (0.95-1.31)
|1.12 (0.95-1.31)
|- align="center"
|13-14
|6
|14 000
|1.13 (0.50-2.52)
|1.13 (0.51-2.53)
|- align="center"
|15-18
|17
|35 000
|1.24 (0.76-2.01)
|1.23 (0.76-2.00)
|- align="center"
|>18
|14
|14 000
|1.92 (1.13-3.26)
|1.89 (1.11-3.22)
|}
<nowiki>*</nowiki> The relative risks were calculated separately for each of the five variables, with adjustment for women's age, calendar period, parity, and age at delivery of a first child. CI denotes confidence interval.<br>
† Values were adjusted for women's age, calendar period, parity, age at delivery of a first child, and the other variables shown in the table.<br>
‡ The women with this characteristic served as the reference group.
Other sections listed age at induced abortion, number of induced abortions, time since induced abortion, and time of induced abortion and live-birth history. There was an indication of a relative risk of 1.29 (0.80-2.08) for 12-19 year olds (relative to 20-24 subcohort), and a protective effect 0.74 (0.41-1.33) for women with an induced abortion before and after their first live birth (relative to induced abortion after 1st live birth subcohort); both results were statistically insignificant.
====Michels====
A study by Dr. Michels ''et al.'' (2007) from the [[Harvard School of Public Health]] containing 105,716 women (233/1,225 ABC cases/controls) concluded with a relative risk of 1.01 (0.88 - 1.17) "after adjustment for established breast cancer risk factors."<ref name="Michels"/> Some of the results lead the study to stipulate: "Although our data are not compatible with any substantial overall relation between induced abortion and breast cancer, we cannot exclude a modest association in subgroups defined by known breast cancer risk factors, timing of abortion, or parity." This modest association was mostly not statistically significant. The following are induced abortion results from Table 4 of the Michels study, with parity distinguished between nulliparous (no children) and parous (had children):<ref name="Michels"/>
{| class="wikitable" border="1" cellpadding="2"
!Parity*
!No. of Breast Cancer Cases†
!No. of Person-Years
!Age-Adjusted HR (95% CI)
!Covariate-Adjusted HR (95% CI)‡
!P Value for the Test of Heterogeneity
|- align="left"
| colspan="6" | '''Nulliparous'''
|- align="center"
| align="center" | No induced abortion
|243§
|159 290
|1 [Reference]
|1 [Reference]
|
|- align="left"
| Abortion
|
|
|
|
|
|- align="center"
| align="left" | ER+
|42
|34 862
|1.27 (0.90-1.79)
|1.25 (0.87-1.78)
| rowspan="2" |.65
|- align="center"
| align="left" | ER−
|14
|34 884
|1.45 (0.79-2.68)
|1.35 (0.71-2.58)
|- align="center"
| align="left" | PR+
|33
|34 865
|1.49 (1.00-2.22)
|1.39 (0.92-2.11)
| rowspan="2" |.73
|- align="center"
| align="left" | PR−
|12
|34 889
|1.25 (0.65-2.40)
|0.97 (0.49-1.93)
|- align="left"
| colspan="6" | '''Parous'''
|- align="center"
| align="center" | No induced abortion
|962<nowiki>||</nowiki>
|642 741
|1 [Reference]
|1 [Reference]
|
|- align="left"
| Abortion
|
|
|
|
|
|- align="center"
| align="left" | ER+
|99
|112 347
|0.99 (0.80-1.23)
|0.95 (0.77-1.18)
| rowspan="2" |.40
|- align="center"
| align="left" | ER−
|35
|112 405
|1.17 (0.81-1.69)
|1.20 (0.83-1.74)
|- align="center"
| align="left" | PR+
|59
|112 382
|0.84 (0.64-1.11)
|0.80 (0.60-1.05)
| rowspan="2" |.002
|- align="center"
| align="left" | PR−
|47
|112 393
|1.62 (1.17-2.23)
|1.58 (1.13-2.20)
|}
Abbreviations: CI, confidence interval; ER+, estrogen receptor positive; ER−, estrogen receptor negative; HR, hazard ratio; PR+, progesterone receptor
positive; PR−, progesterone receptor negative.
<nowiki>*</nowiki> Parity status was updated in the regression analysis at every 2-year interval. The number of women who were nulliparous and reported spontaneous abortions was too small to calculate reasonably stable estimates.
† Cases with ER information and cases with PR information may overlap.
‡ The HRs and 95% CIs among nulliparous women were adjusted for age, birth weight, premature birth, family history of breast cancer, history of benign breast
disease, height, body mass index at the age of 18 years and current body mass index (calculated as weight in kilograms divided by height in meters squared), age at menarche, oral contraceptive use, alcohol consumption, physical activity, menopausal status, age at menopause, and postmenopausal hormone use. The HRs
and 95% CIs among parous women were adjusted for the same covariates as the HRs and 95% CIs among nulliparous women and in addition for parity and age
at first birth.
§ Total number of cases, including 149 ER+ and 42 ER− (a total of 191 cases with known ER status), and 99 PR+ and 41 PR− (a total of 140 cases with known
PR status) cases. The incidence of breast cancer with corresponding ER/PR status was used when calculating HRs of ER+, ER−, PR+, and PR− breast cancer.
<nowiki>||</nowiki> Total number of cases, including 586 ER+ and 174 ER− (a total of 760 cases with known ER status), and 413 PR+ and 172 PR− (a total of 585 cases with known PR status) cases. The incidence of breast cancer with corresponding ER/PR status was used when calculating HRs of ER+, ER−, PR+, and PR− breast
cancer.
====Further cohort studies====
Several other recent prospective [[Cohort study|cohort studies]] have also found little evidence of a link between induced abortion and breast cancer. A study of 267,361 European women (746/2,908 ABC cases/controls), published in 2006, found no significant ABC risk.<ref name="epic">{{cite journal |author=Reeves G, Kan S, Key T, Tjønneland A, Olsen A, Overvad K, Peeters P, Clavel-Chapelon F, Paoletti X, Berrino F, Krogh V, Palli D, Tumino R, Panico S, Vineis P, Gonzalez C, Ardanaz E, Martinez C, Amiano P, Quiros J, Tormo M, Khaw K, Trichopoulou A, Psaltopoulou T, Kalapothaki V, Nagel G, Chang-Claude J, Boeing H, Lahmann P, Wirfält E, Kaaks R, Riboli E |title=Breast cancer risk in relation to abortion: Results from the EPIC study |journal=Int. J. Cancer |volume=119 |issue=7 |pages=1741–5 |year=2006 |pmid=16646050 |doi=10.1002/ijc.22001}}</ref> Another 2006 study involving 267,400 women (872/771 ABC cases/controls) in [[Shanghai]] found no evidence of an ABC link. The Shanghai study also noted that women who had an abortion were at a significantly ''decreased'' risk of uterine cancer.<ref name="shanghai">{{cite journal |author=Rosenblatt K, Gao D, Ray R, Rowland M, Nelson Z, Wernli K, Li W, Thomas D |title=Induced abortions and the risk of all cancers combined and site-specific cancers in Shanghai |journal=Cancer Causes Control |volume=17 |issue=10 |pages=1275–80 |year=2006 |pmid=17111259 |doi=10.1007/s10552-006-0067-x}}</ref>
===Meta-analysis===
====Beral====
In March 2004, Dr. Beral ''et al.'' published a study in ''[[The Lancet]]'' as a collaborative reanalysis on ''Breast cancer and abortion''.<ref name="BERAL">{{cite journal |author=Beral V, Bull D, Doll R, Peto R, Reeves G |title=Breast cancer and abortion: collaborative reanalysis of data from 53 epidemiological studies, including 83?000 women with breast cancer from 16 countries |journal=Lancet |volume=363 |issue=9414 |pages=1007–16 |year=2004 |pmid=15051280 |doi=10.1016/S0140-6736(04)15835-2}}</ref> This meta-analysis of 53 epidemiologic studies of 83,000 women with breast cancer undertaken in 16 countries did not find evidence of a relationship between induced abortion and breast cancer, with a relative risk of 0.93 (0.89 - 0.96). Organizations and media outlets referenced the Beral study as the most comprehensive overview of the ABC evidence.<ref name="beral_post)">{{cite web |url=http://www.washingtonpost.com/ac2/wp-dyn?pagename=article&node=&contentId=A25076-2004Mar25¬Found=true |title=Abortion's Link to Breast Cancer Discounted |accessdate=2008-04-14 |format= |work=washingtonpost.com |author=Shankar Vedantam |date=March 26, 2004}}</ref><ref name="beral_nyt">{{cite web |url=http://www.nytimes.com/2004/03/25/health/25CND-ABORT.html?ei=5070&en=66a47746dbc96f40&ex=1208404800&adxnnl=1&adxnnlx=1208232765-You1/UPj1lwa6V9DBNhBFg |title=Abortions Do Not Raise Risk of Breast Cancer, Study Says |accessdate=2008-04-14 |format= |work=nytimes.com |author=Lawrence K. Altman |date=March 25, 2004}}</ref>
Dr. Brind maintains that like meta-analysis this study is subject to [[selection bias]], which he believes is reflected in the removal of 15 published, peer-reviewed studies with positive ABC results for "unscientific reasons"; and including 28 unpublished studies that outnumber the remaining 24 peer reviewed studies.<ref name="BRIND FS">{{cite web |url=http://bcpinstitute.org/beralpaperanalysis.htm |title=Breast Cancer Prevention Institute Fact Sheets |accessdate=2007-11-04 |format= |work=}}</ref> Beral refers to the Lindefors-Harris response bias study as an explaination for higher ABC risk found in interview based studies,<ref name="LH1991"/> however Brind notes in 1998 that Lindefors-Harris conceded their initial conclusion may have been unsound.<ref name="MEIRIK">{{cite journal |author=Meirik O, Adami HO, Eklund G |title=Relation between induced abortion and breast cancer |journal=Journal of epidemiology and community health |volume=52 |issue=3 |pages=209–11 |year=1998 |pmid=9616432 |doi=}}</ref>
====Brind====
Dr. Brind ''et al.'' (1996) conducted a meta-analysis of 23 epidemiologic studies.<ref name="BRIND">{{cite journal |author=Brind J, Chinchilli VM, Severs WB, Summy-Long J |title=Induced abortion as an independent risk factor for breast cancer: a comprehensive review and meta-analysis |journal=Journal of epidemiology and community health |volume=50 |issue=5 |pages=481–96 |year=1996 |pmid=8944853 |doi=}}</ref> It calculated that there was on average a relative risk of 1.3 (1.2 - 1.4) increased risk of breast cancer. The meta-analysis was criticized for [[selection bias]] by using studies with widely varying results, using different types of studies, not working with the raw data from several studies, and including studies that have possible methodological weaknesses.<ref name="WEED"/>
The [[Royal College of Obstetricians and Gynaecologists]] (RCOG) in March 2000 published evidence-based guidelines on women requesting induced abortion. The review of the available evidence at the time was "inconclusive" regarding the ABC link. They also noted "Brind's paper had no methodological shortcomings and could not be disregarded."<ref name="rcog_2000">{{cite web |url=http://www.rcog.org.uk/resources/Public/pdf/induced_abortionfull.pdf |title=The Care of Women Requesting Induced Abortion |page=43 |format=PDF |work= |accessdate=2008-06-29}}</ref> However, in 2003 the RCOG concluded that there was no link between abortion and breast cancer.<ref>{{cite web |url=http://www.rcog.org.uk/resources/Public/pdf/induced_abortionfull.pdf |title=The Care of Women Requesting Induced Abortion |accessdate=2007-11-07 |format= |work=Royal College of Obstetricians and Gynaecologists}}</ref> Some of the ABC studies RCOG reference as evidence (pg. 77) have been heavily criticized by Brind in 2005.<ref name="Brind2005">{{cite web |url=http://www.jpands.org/vol10no4/brind.pdf |title=A Critical Review of Recent Studies Based on Prospective Data |accessdate=2008-04-01 |format= |work=jpands.org |author=Joel Brind}}</ref>
===Interviews===
Interview (case-control) based studies have been inconsistent on the ABC hypothesis. With the small numbers involved in each individual study and the possibility that recall bias skewed the results, recent focus has switched to meta-analysis and record based studies which are typically much larger.<ref>{{cite web |url=http://www.religioustolerance.org/abo_canc.htm |title=Is there a link between abortion and breast cancer? A balanced review |accessdate=2007-11-04 |format= |work=religioustolerance.org}}</ref> Included are a few interview studies of note.
====Daling====
Dr. Janet Daling from the [[Fred Hutchinson Cancer Research Center]] headed two studies on the ABC issue looking at women in Washington state. The 1994 study (845/961 ABC cases/controls) results indicated an associated relative risk of 1.5 (1.2 - 1.9) among women who had given birth before having an abortion.<ref name="DALING">{{cite journal |author=Daling JR, Malone KE, Voigt LF, White E, Weiss NS |title=Risk of breast cancer among young women: relationship to induced abortion |journal=J. Natl. Cancer Inst. |volume=86 |issue=21 |pages=1584–92 |year=1994 |pmid=7932822 |doi=10.1093/jnci/86.21.1584}}</ref> This was reflected in higher risks for women younger than 18 or older than 30 years of age who have had abortions after 8 weeks' gestation. Their conclusion emphasized that although the evidence suggested the possibility of a correlative relationship, their findings were not consistent enough to establish one.
The second larger study Daling conducted in 1996 (1,302/1,180 ABC cases/controls) found that abortion was associated with a relative risk value of 1.2 (1.0 - 1.5).<ref name="DALING2"/> The study also found a significant relative risk of 2.0 (1.2 - 3.3) for nulliparous women with an induced abortion at less than 8 weeks gestation. Daling ''et al.'' concluded that:
{{cquote|There was no excess risk of breast cancer associated with induced abortion among parous women. These data support the hypothesis that there may be a small increase in the risk of breast cancer related to a history of induced abortion among young women of reproductive age. However, the data from this study and others do not permit a causal interpretation at this time; neither do the collective results of the studies suggest that there is a subgroup of women in whom the relative risk associated with induced abortion is unusually high.<ref name="DALING2"/>}}
Dr. Daling ''et al.'' examined the possibility of response bias by comparing results from two recent studies on invasive cervical cancer and ovarian cancer. The results argued against significant response bias. However, Rookus (1996) study noted that patients with cervical cancer may report differently than breast cancer patients.<ref name="ROOKUS">{{cite journal |author=Rookus MA, van Leeuwen FE |title=Induced abortion and risk for breast cancer: reporting (recall) bias in a Dutch case-control study |journal=J. Natl. Cancer Inst. |volume=88 |issue=23 |pages=1759–64 |year=1996 |pmid=8944006 |doi=10.1093/jnci/88.23.1759}}</ref>
====Sanderson====
A 2001 study (1,459/1,556 ABC cases/controls) conducted in [[Shanghai]], [[China]] by Dr. Sanderson ''et al.'' from the [[University of South Carolina]] and South Carolina Cancer Center at [[Columbia, South Carolina|Columbia]] concluded that there was no ABC link and that multiple abortions did not put one at greater risk.<ref name="sanderson">{{cite journal |author=Sanderson M, Shu XO, Jin F, ''et al'' |title=Abortion history and breast cancer risk: results from the Shanghai Breast Cancer Study |journal=Int. J. Cancer |volume=92 |issue=6 |pages=899–905 |year=2001 |pmid=11351314 |doi=10.1002/ijc.1263}}</ref> Since induced abortion is common, legal, and even mandated by the government in China, the recall bias was minimized.
Brind has argued that the same factors that make the Chinese study ideal for reducing recall bias also makes them inappropriate for comparison to the West.<ref>{{cite journal |author=Brind J, Chinchilli VM |title=Breast cancer and induced abortions in China |journal=Br. J. Cancer |volume=90 |issue=11 |pages=2244–5; author reply 2245–6 |year=2004 |pmid=15150586 |doi=10.1038/sj.bjc.6601853}}</ref> Specifically, with China’s strict population control, the vast majority of the abortions in the Chinese study were done after the first full-term pregnancy.<ref name="sanderson"/> This differs from [[North America]].<ref name="GUTTMACHER">{{cite web |url=http://www.guttmacher.org/pubs/fb_induced_abortion.html |title=Facts on Induced Abortion in the United States |accessdate=2007-11-04 |format= |work=guttmacher.org}}</ref>
====Response bias====
[[Image:BreastCancer ChrisKahlenborn.gif|thumb|210px|Book cover of ''Breast Cancer: Its Link to Abortion and the Birth Control Pill'']]
[[Response bias]] occurs when women intentionally "underreport" their abortion history, meaning that they deny having an abortion or claim to have fewer abortions than they actually had. This can happen because of the personal and controversial nature of abortion, which may cause women to not want to provide full disclosure. Women in control groups are less likely to have serious illnesses, and hence have less motivation to be truthful than those trying to diagnose their problem.<ref name="ROOKUS"/> When this occurs, it artificially creates an ABC link where none exists. Three major studies have been published examining abortion response bias.
An editorial by Drs. Weed and Kramer focused on how [[Abortion-breast cancer hypothesis#Brind|Brind's meta-analysis]] dismissed bias as a factor. The editorial cites the Lindefors-Harris [[Abortion-breast_cancer_hypothesis#Lindefors-Harris_2|response bias study]] that used a "registry-based gold standard to show that healthy women consistently and widely underreport their history of abortion."<ref name="LH1991"/><ref name="WEED"/> Drs. Weed and Kramer considered this compelling evidence there could be systematic bias within the studies included in the meta-analysis. However, subsequently the Lindefors-Harris conclusion was quietly retracted in 1998.<ref name="MEIRIK"/> Drs. Weed and Kramer believed a causal conclusion was a "leap beyond the bounds of inference" and concluded:
<blockquote>
Because bias impedes our vision ''and'' is subject to sound inquiry, we are far from reaching a scientific "limit". Indeed, after this excursion into the issue of abortion, bias, and breast cancer, it seems our future has as much to do with human behavior as with human biology.<ref name="WEED">{{cite journal |author=Weed DL, Kramer BS |title=Induced abortion, bias, and breast cancer: why epidemiology hasn't reached its limit |journal=J. Natl. Cancer Inst. |volume=88 |issue=23 |pages=1698–700 |year=1996 |pmid=8943995 |doi=10.1093/jnci/88.23.1698}}</ref>
</blockquote>
A review of ABC studies was conducted by Dr. Bartholomew in 1998. It concluded that if studies least susceptible to response bias are considered, they suggest there is no association between abortion and breast cancer.<ref name="BARTHOLOMEW">{{cite journal |author=Bartholomew LL, Grimes DA |title=The alleged association between induced abortion and risk of breast cancer: biology or bias? |journal=Obstetrical & gynecological survey |volume=53 |issue=11 |pages=708–14 |year=1998 |pmid=9812330 |doi=}}</ref> Chris Kahlenborn, M.D., a pro-life researcher and specialist in internal medicine, observes in his book ''Breast Cancer: Its Link to Abortion and the Birth Control Pill'' that if report bias were a significant factor in interview-based studies, then:
<blockquote>
... thousands of other studies in medicine might now be deemed 'worthless.' Every time one had a disease or 'effect' that was caused by a controversial risk factor (i.e., one of the causes), the study might be considered invalid based upon 'recall bias.'<ref name="Catholic Citizens">{{cite web |url=http://catholiccitizens.org/platform/platformview.asp?c=4654 |title=Catholic Citizens |accessdate=2008-01-21 |format=HTML |work=CatholicCitizens.org title|=Abortion and Breast Cancer: The Scientific Debate That Never Happened |author=Karen Malec}}</ref>
</blockquote>
=====Lindefors-Harris=====
The Lindefors-Harris (1991) study (317/512 ABC cases/controls) was the first major study to examine response and recall bias.<ref name="LH1991">{{cite journal |author=Lindefors-Harris BM, Eklund G, Adami HO, Meirik O |title=Response bias in a case-control study: analysis utilizing comparative data concerning legal abortions from two independent Swedish studies |journal=Am. J. Epidemiol. |volume=134 |issue=9 |pages=1003–8 |year=1991 |pmid=1951288 |doi=}}</ref> It used the data of two independent [[Sweden|Swedish]] induced abortion studies, and concluded there was a 1.5 (1.1 - 2.1) margin of error due to recall bias. However, eight women (seven cases, one control) included in this error margin apparently "overreported" their abortions, meaning the women reported having an abortion that was not reflected in the records. It was decided that for the purposes of the study, these women did not have abortions.<ref name="LH1991"/>
The 1994 Daling study examined the findings on overreporting of the Lindefors-Harris study and found it "reasonable to assume that virtually no women who truly did not have an abortion would claim to have had one,"<ref name="DALING"/> and missing records could have occurred for a variety of reasons. With these eight women removed, the error margin was reduced from 50% to 16% which severely limited its statistical significance. Dr. Brind believes the remaining 16% could have resulted from the Swedish fertility registry<ref>{{cite journal |author=Meirik O, Lund E, Adami HO, Bergström R, Christoffersen T, Bergsjö P |title=Oral contraceptive use and breast cancer in young women. A joint national case-control study in Sweden and Norway |journal=Lancet |volume=2 |issue=8508 |pages=650–4 |year=1986 |pmid=2876135 |doi=10.1016/S0140-6736(86)90166-2}}</ref>{{ndash}} where women were interviewed as mothers{{ndash}} which could have increased their tendency to underreport, given that a mother might not want to appear unfit.<ref name="BRIND"/> Subsequently Dr. Lindefors-Harris retracted the 50% conclusion in 1998, but they reasserted since the Melbye cohort study in 1997 found no significant ABC risk, the 30% increased risk in the Brind meta-analysis must be the accumulative result of response bias.<ref name="MEIRIK"/>
=====Rookus=====
The Rookus (1996) study (918 ABC cases/controls) compared two regions in the [[Netherlands]] to assess the effect of [[religion]] on ABC results based on interviews.<ref name="ROOKUS"/> The [[secular]] (western) and [[Social conservatism|conservative]] (southeastern) regions showed ABC relative risks of 1.3 (0.7 - 2.6) and 14.6 (1.8 - 120.0) respectively. Although this was a large variance, Brind ''et al.'' pointed out that it was attained with an extremely small sample size.<ref>{{cite journal |author=Brind J, Chinchilli VM, Severs WB, Summy-Long J |title=Re: Induced abortion and risk for breast cancer: reporting (recall) bias in a Dutch case-control study |journal=J. Natl. Cancer Inst. |volume=89 |issue=8 |pages=588–90 |year=1997 |pmid=9106653 |doi=10.1093/jnci/89.8.588}}</ref> (12 cases and 1 control)
Dr. Rookus ''et al.'' supported their finding with an analysis of how much recall bias existed with oral [[contraceptive]] use that could be verified through records. It corroborated the bias, but Dr. Brind's ''et al.'' letter argues that it only indicated response bias between the two regions, not between case and control subjects within regions. Dr. Rookus ''et al.'' responded by noting that there was a 4.5 month underreporting difference between control and case subjects in the conservative Catholic region. This was indirect evidence for a reporting bias since women's comfort levels with reporting oral contraception are theoretically higher than induced abortion. Rookus ''et al.'' also acknowledged the weakness in the Lindefors-Harris response bias study,<ref name="LH1991"/> but emphasized that more controls (16/59 = 27.1%) than case patients (5/24 = 20.8%) underreported registered induced abortions. They concluded that asserting a causal ABC link would be a disservice to the public and to epidemiological research when "bias has not been ruled out convincingly."<ref name="ROOKUS"/>
=====Tang=====
A study by Dr. Tang ''et. al.'' (2000) (225/303 ABC cases/controls) done in Washington State found controls were not more reluctant to report induced abortion than women with breast cancer.<ref name="Tang">{{cite journal |author=Tang MT, Weiss NS, Daling JR, Malone KE |title=Case-control differences in the reliability of reporting a history of induced abortion |journal=Am. J. Epidemiol. |volume=151 |issue=12 |pages=1139–43 |year=2000 |pmid=10905525 |doi=}}</ref> Their results were that 14.0% of cases and 14.9% controls (a difference of -0.9%) did not accurately report their abortion history. They do note likely underreporting occurring in certain sub-groups of women; such as older women in a Newcomb study reporting abortions prior to legalization,<ref name="Newcomb">{{cite journal |author=Newcomb PA, Storer BE, Longnecker MP, Mittendorf R, Greenberg ER, Willett WC |title=Pregnancy termination in relation to risk of breast cancer |journal=JAMA |volume=275 |issue=4 |pages=283–7 |year=1996 |pmid=8544267 |doi=10.1001/jama.275.4.283}}</ref> and a predominantly [[Roman Catholic Church|Roman Catholic]] population in the Rookus study.<ref name="ROOKUS"/>
===Spontaneous abortion===
Studies of spontaneous abortions ([[miscarriage]]s) have generally shown no increase in breast cancer risk,<ref>{{cite journal |author=Brewster DH, Stockton DL, Dobbie R, Bull D, Beral V |title=Risk of breast cancer after miscarriage or induced abortion: a Scottish record linkage case-control study |journal=Journal of epidemiology and community health |volume=59 |issue=4 |pages=283–7 |year=2005 |pmid=15767381 |doi=10.1136/jech.2004.026393}}</ref> although a study by Dr. Paoletti concluded there is a "suggestion of increased risk" 1.2 (0.92 - 1.56) after three or more pregnancy losses.<ref>{{cite journal |author=Paoletti X, Clavel-Chapelon F |title=Induced and spontaneous abortion and breast cancer risk: results from the E3N cohort study |journal=Int. J. Cancer |volume=106 |issue=2 |pages=270–6 |year=2003 |pmid=12800205 |doi=10.1002/ijc.11203}}</ref> Some argue that this apparent lack of effect of miscarriages on breast cancer risk is evidence against the ABC hypothesis, and some pro-choice advocates have claimed it is proof that neither early pregnancy loss nor abortion are risk factors for breast cancer.<ref name="ARTHUR"/>
One of the problems with comparing miscarriage to abortion is the issue of hormone levels in early pregnancy, a key point because the ABC hypothesis rests on hormonal influence over breast tissue development. While it is true most miscarriages are not ''caused'' by low hormones, most miscarriages are ''characterized'' by low hormone levels.<ref>{{cite web |url=http://web.archive.org/web/20050307221417/http://www.st-marys.nhs.uk/specialist/miscarriage_clinic/causes.htm |title=The Recurrent Miscarriage Clinic - What Causes Recurrent Miscarriage? |accessdate=2007-11-04 |format= |work=st-marys.nhs.uk}}</ref> Kunz & Keller (1976) showed that when [[progesterone]] is abnormally low a miscarriage occurs 89% of the time.<ref>{{cite journal |author=Kunz J, Keller PJ |title=HCG, HPL, oestradiol, progesterone and AFP in serum in patients with threatened abortion |journal=British journal of obstetrics and gynaecology |volume=83 |issue=8 |pages=640–4 |year=1976 |pmid=60125 |doi=}}</ref> Advocates of the ABC hypothesis argue that, given the association of most first trimester miscarriages with low hormone levels, spontaneous abortion is not analogous to an induced abortion.
==Politicization==
[[Image:Abc waco billboard.jpg|thumb|left|260px|ABC billboard in [[Waco, Texas]] referring to the [[Race for the Cure|Komen Race for the Cure]].]]
Public interest in an association between abortion and breast cancer coincided with the rise of the militant pro-life movement which turned to [[Abortion related violence|violence]]. However, the 1993 murder of physician [[Abortion related violence|David Gunn]] by a pro-life activist "irreparably harmed the movement". In response to the escalating violence, President Bill Clinton signed the [[Freedom of Access to Clinic Entrances Act]] (FACE) and clinic "buffer zones" were established to protect women and clinic employees. Though militant pro-life activists continued to bomb clinics and kill employees, their violence caused mainstream pro-life organizations to disavow their methods.<ref name="JASEN"/>
Pro-life organizations like National Right to Life turned to legal tactics that included lobbying against late-term abortions and [[RU-486]]. One of the other tactics adopted by the mainstream pro-life movement was promoting an alleged "ABC link". During the height of a publicized "breast cancer epidemic" pro-life organizations began to emphasize preliminary positive ABC results in an effort to further restrict abortion and to discourage women from having abortions.<ref name="JASEN"/> Currently, pro-life organizations lobby to increase obstacles to abortion, such as mandated [[counseling]], waiting periods, and parental notification,<ref name="GUTTMACHER">{{cite web |url=http://www.guttmacher.org/pubs/fb_induced_abortion.html |title=Facts on Induced Abortion in the United States |accessdate=2007-11-04 |format= |work=guttmacher.org}}</ref> and some feel that pro-life advocates treat ABC as simply another tactic in their campaign against abortion.<ref name="ARTHUR"/> There have been ongoing and incremental legal challenges to abortion in the United States by pro-life groups.<ref>{{cite web |url=http://www.pbs.org/wgbh/pages/frontline/clinic/ |title=The Last Abortion Clinic |accessdate=2007-11-04 |format= |work=PBS.org}}</ref> In 2005, a [[Canada|Canadian]] pro-life organization put up [[billboard (advertising)|billboard]]s in [[Alberta]] with large [[Pink ribbon#Breast cancer awareness|pink ribbon]]s and the statement: "Stop the Cover-Up," in reference to the ABC hypothesis.<ref>{{cite web |url=http://www.cbc.ca/health/story/2005/10/25/pink-ribbon051025.html |title=Group angered by billboards linking breast cancer to abortion |accessdate=2007-11-04 |format= |work=cbc.ca}}</ref> The [[Canadian Breast Cancer Foundation]] was concerned the billboards misrepresented the state of scientific knowledge on the subject.<ref name="BERAL"/>
The continued focus on the "ABC link" by pro-life groups has created a confrontational political environment. Pro-choice advocates and scientists alike have responded with criticisms.<ref name="JASEN"/><ref name="MELBYE"/><ref name="WEED"/> The claims by pro-life advocates are sometimes referred to as [[pseudoscience]].<ref>{{cite web |url=http://www.goldenboob.org/ |title=Vote for the Golden Boob! |accessdate=2007-11-04 |format=HTML |work=goldenboob.org}}</ref><ref name="CRLP"/> The extent with which politics has infused the ABC issue is illustrated by an editorial that quoted [[Abortion-breast_cancer_hypothesis#Daling|Dr. Daling]] as saying:
{{cquote|If politics gets involved in science, it will really hold back the progress we make. I have three sisters with breast cancer, and I resent people messing with the scientific data to further their own agenda, be they pro-choice or pro-life. I would have loved to have found no association between breast cancer and abortion, but our research is rock solid, and our data is accurate. It's not a matter of believing. It's a matter of what is.<ref name="GELMAN">{{cite web |url=http://www.thefreelibrary.com/FINDINGS+LINKING+CANCER+TO+ABORTIONS+A+WELL-KEPT+SECRET-a083942541 |title=FINDINGS LINKING CANCER TO ABORTIONS A WELL-KEPT SECRET. - Free Online Library |accessdate=2007-12-30 |format= |author=Joe Gelman |work=L.A. Daily News}}</ref><ref>[http://www.theage.com.au/articles/2003/02/16/1045330466585.html theage.com.au]{{ndash}} Breast cancer and abortion: the facts</ref>}}
During the late 1990s several United States [[Member of Congress|congressmen]] became involved in the ABC issue. In 1998, congressman [[Tom Coburn]] questioned a National Cancer Institute (NCI) official on why the NCI website contained out of date information on the ABC issue.<ref>{{cite web |url=http://www.physiciansforlife.org/content/view/105/26/ |title=Physicians For Life - Abstinence, Abortion, Birth Control - Need to Inform Patients of Abortion - Breast Cancer Link |accessdate=2007-11-04 |format= |work=physiciansforlife.org}}</ref> Congressman [[Dave Weldon]] wrote a "Dear Colleague" letter to congress in 1999 shortly after the House debated [[Food and Drug Administration|FDA]] approval of the abortion drug [[Mifepristone]]; and partially as a result of John Kindley's law review on informed consent which was enclosed.<ref name="KINDLEY"/> In it Weldon expressed concern that the majority of studies indicate a possible ABC link and the politicization of the ABC issue is "preventing vital information from being given to women."<ref name="Weldon">{{cite web |url=http://www.abortionbreastcancer.com/weldon_letter.htm |title=Weldon Letter |accessdate=2007-11-04 |format= |work=abortionbreastcancer.com}}</ref>
As of 2004, state law in [[Minnesota]], [[Mississippi]], [[Texas]], [[Louisiana]], and [[Kansas]] requires warning women seeking abortions about a possible breast cancer risk. Similar [[legislation]] requiring notification has also been introduced, and was pending, in 14 other [[U.S. state|states]].<ref>{{cite web |url=http://www.boston.com/news/nation/articles/2004/11/10/questions_on_states_abortion_warnings/?rss_id=Boston%20Globe%20--%20National%20News |title=Questions on states' abortion warnings |accessdate=2007-11-04 |format= |work=The Boston Globe}}</ref> An editor for the [[American Journal of Public Health]] expressed concern over how such legislative bills propose warnings that do not agree with established scientific findings.<ref name="Chavkin">{{cite journal |author=Chavkin W |title=Topics for our times: public health on the line--abortion and beyond |journal=American journal of public health |volume=86 |issue=9 |pages=1204–6 |year=1996 |pmid=8806368}}</ref> However, it is possible that such legally-mandated disclosure could mitigate possible future [[lawsuit]]s involving [[informed consent]] from women who might contend they should have been told of the ABC hypothesis possibility prior to having an abortion.<ref>{{cite web |url=http://www.piercelaw.edu/risk/vol2/winter/merz.htm |title=Medical Informed Consent |accessdate=2007-11-04 |format= |work=piercelaw.edu}}</ref>
===National Cancer Institute===
A report from the [[United States House Committee on Oversight and Government Reform|Committee on Oversight and Government Reform]] found that in November 2002, the [[Presidency of George W. Bush|Bush administration]] altered the [[National Cancer Institute]]'s (NCI) website. The previous NCI analysis had concluded that while some question regarding an association between abortion and breast cancer existed prior to the mid-1990s, a number of large and well-regarded studies such as Melbye ''et al.'' (1997) had resolved the issue; and there was no link between abortion and breast cancer. The Bush administration removed this analysis and replaced it with the following:
{{cquote|[T]he possible relationship between abortion and breast cancer has been examined in over thirty published studies since 1957. Some studies have reported statistically significant evidence of an increased risk of breast cancer in women who have had abortions, while others have merely suggested an increased risk. Other studies have found no increase in risk among women who have had an interrupted pregnancy.<ref name="HOUSE">{{cite web |url=http://democrats.reform.house.gov/features/politics_and_science/example_breast_cancer.htm |title=Politics & Science - Investigating the State of Science Under the Bush Administration |accessdate=2007-11-04 |format= |work=democrats.reform.house.gov}}</ref>}}
This alteration, which suggested that there was scientific uncertainty on the ABC issue, prompted an editorial in the [[New York Times]] describing it as an "egregious distortion" and a letter to the [[Secretary of Health and Human Services]] from members of Congress.<ref name="HOUSE"/> In response to the alteration, NCI convened a three-day consensus workshop. The workshop concluded that induced abortion does not increase a woman's risk of breast cancer, and that the evidence for this was well-established.<ref name="NCI"/> Afterwards, the director of epidemiology research for the American Cancer Society said, “This issue has been resolved scientifically . . . . This is essentially a political debate."<ref name="HOUSE"/>
Dr. Brind was the only one to file a dissenting opinion as a minority report criticizing the NCI's and Dr. Melbye's conclusions.<ref name="MINORITY">{{cite web |url=http://www.bcpinstitute.org/nci_minority_rpt.htm |title=Breast Cancer Prevention Institute |accessdate=2007-11-04 |format= |work=bcpinstitute.org}}</ref><ref>{{cite web |url=http://cancer.gov/cancer_information/doc.aspx?viewid=15e3f2d5-5cdd-4697-a2ba-f3388d732642 |title=Minority Dissenting Comment - National Cancer Institute |accessdate=2007-11-04 |format= |work=}}</ref> Brind alleges the workshop evidence and findings were overly controlled by its organizers since Dr. Daling, who has published on the abortion-breast cancer issue, was asked to present on another topic; and Dr. Melbye submitted unpublished data during the workshop instead allowing attendees to review it beforehand.<ref name="USATODAY">{{cite web |url=http://www.usatoday.com/news/health/2003-02-26-cancer-usat_x.htm |title=USATODAY.com - No breast cancer-abortion link |format= |work=USA TODAY |accessdate=2008-06-29}}</ref><ref name="MINORITY"/> Preterm delivery was listed as an epidemiological "gap" even though there was preliminary evidence of a correlation with higher breast cancer risk.<ref name="MELBYE2">{{cite journal |author=Melbye M, Wohlfahrt J, Andersen AM, Westergaard T, Andersen PK |title=Preterm delivery and risk of breast cancer |journal=Br. J. Cancer |volume=80 |issue=3-4 |pages=609–13 |year=1999 |pmid=10408874 |doi=10.1038/sj.bjc.6690399}}</ref>
Dr. Jasen notes: "A very public target of the anti-abortion movement has been the National Cancer Institute, not only for its dismissal of Daling's findings and uncritical support of Melbye's report, but also for the information supplied on its website, which potentially reaches millions of women around the world."<ref name="JASEN"/> Dr. Lawrence R. Huntoon editor-in-chief for the conservative non-mainstream ''[[Journal of American Physicians and Surgeons]]'' notes in a Malec article that while the workshop had over 100 experts who voted on the findings the NCI website does not elaborate on the vote results.<ref name="MALEC">{{cite web |url=http://www.jpands.org/vol8no2/malec.pdf |title=The Abortion-Breast Cancer Link: How Politics Trumped Science and Informed Consent |accessdate=2008-03-30 |format=PDF |work=Journal of American Physicians and Surgeons}}</ref>
===North Dakota lawsuit===
One example of the politicization of science is the case of ''Kjolsrud v. MKB Management Corporation''. In January 2000, Amy Jo Kjolsrud (née Mattson), a pro-life counselor, sued the Red River Women's Clinic in [[Fargo, North Dakota]] alleging false [[advertising]].<ref>{{cite web |url=http://www.redriverwomensclinic.com |title=Abortion Clinic of Fargo |accessdate=2007-11-04 |format= |work=redriverwomensclinic.com}}</ref> The suit alleged the clinic was misleading women by distributing a brochure quoting a National Cancer Institute fact sheet on the ABC issue which stated:
:"Anti-abortion activists claim that having an abortion increases the risk of developing breast cancer and endangers future childbearing. '''None''' of these claims are supported by medical research or established medical organizations."<ref>{{cite web |url=http://www.religioustolerance.org/abo_canc1.htm |title=Is there a link between abortion and breast cancer? A balanced review |accessdate=2007-11-04 |format= |work=religioustolerance.org}}</ref> (emphasis in original)
The case was originally scheduled for [[September 11]], [[2001]], but was delayed as a result of the [[September 11, 2001 attacks|terrorist attacks]]. On [[March 25]], [[2002]], the trial started and after four days of testimony, Judge Michael McGuire ruled in favor of the clinic. In his decision, he said:
{{cquote|It does appear that the clinic had the intent to put out correct information and that their information is not untrue or misleading in any way. They did exercise reasonable care... One thing is clear from the experts, and that is that there are inconsistencies. The issue seems to be in a state of flux.}}
The judge noted it was their "intent" to provide accurate information because the brochure used an outdated 1996 fact sheet that stated there was "no established link", instead of the 1999 fact sheet wording of "inconsistent" evidence for the ABC issue.<ref>{{cite web |url=http://www.beyondmainstream.com/archives/politics/feminist/abortion_breast_cancer.php |title=Beyond Mainstream - alternative news, progressive politics, holistic healing, humor jokes, alternative media, alternative culture |accessdate=2007-10-20 |format= |work=}}</ref><ref>{{cite web |url=http://www.worldnetdaily.com/news/article.asp?ARTICLE_ID=27027 |title=Judge rules in favor of abortion clinic |accessdate=2007-11-04 |format= |work=WorldNetDaily.com}}</ref> [[Linda Rosenthal]], an attorney from the Center for Reproductive Rights characterized the decision thusly: "The judge rejected the abortion-breast cancer scare tactic. This ruling should put to rest the unethical, anti-choice scare tactic of using pseudo-science to harass abortion clinics and scare women."<ref name="CRLP">{{cite web |url=http://crlp.org/pr_02_0328ND.html |title=ARCHIVE| 3/28/02 - Judge Rejects Abortion-Breast Cancer Scare Tactic |accessdate=2007-11-04 |format= |work=crlp.org}}</ref>
John Kindley, one of the lawyers representing Ms. Kjolsrud stated: "I think most citizens, whether they are pro-choice or pro-life, believe in an individual's right to self-determination. They believe people shouldn't be misled and should be told about [procedural] risks, even if there is controversy over those risks."<ref>{{cite web |url=http://www.womenspress.com/main.asp?Search=1&ArticleID=1580&SectionID=1&SubSectionID=1&S=1 |title=Controversy over alleged breast cancer link lands abortion clinic in court |accessdate=2007-11-04 |format= |work=womenspress.com}}</ref> Kindley also wrote an article published in 1998 by the [[Wisconsin Law Review]] outlining the viability of [[medical malpractice]] lawsuits based upon not informing patients considering abortion about the evidence indicating an ABC link.<ref name="KINDLEY">{{cite web |url=http://johnkindley.com/johnak/p4.html |title=John A. Kindley Law Office: The ABC Link |accessdate=2007-11-07 |format= |work=John Kindley}}</ref>
The decision was appealed and on [[September 23]], [[2003]], to the [[North Dakota Supreme Court]] which ruled the false advertising law should not have been used by Ms. Kjolsrud.<ref>{{cite web |url=http://www.legis.nd.gov/cencode/t51c12.pdf |title=CHAPTER 51-12 FALSE ADVERTISING |accessdate=2007-11-04 |format= |work=legis.nd.gov}}</ref> This was because she personally had suffered no injury and hence had no standing (according to North Dakota [[jurisprudence]]) to file the lawsuit on behalf of others. In the appeal, Ms. Kjolsrud "concedes she had not read the brochures before filing her action."<ref>{{cite web |url=http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=nd&vol=20030023&invol=1 |title=Amy Jo Kjolsrud v. MKB Management Corporation |accessdate=2007-11-04 |format= |work=}}</ref> However, the appeal also noted that after the lawsuit was filed the abortion clinic updated their brochure to the following:
:"Some anti-abortion activists claim that having an abortion increases the risk of developing breast cancer. A substantial body of medical research indicates that there is no established link between abortion and breast cancer. In fact, the National Cancer Institute has stated, '[t]here is no evidence of a direct relationship between breast cancer and either induced or spontaneous abortion.'"
===Carroll===
In the Fall of 2007, Patrick S. Carroll published a statistical analysis in the ''[[Association of American Physicians and Surgeons#Journal of American Physicians and Surgeons|Journal of American Physicians and Surgeons]]'',<ref>[http://www.jpands.org/vol12no3/carroll.pdf The Breast Cancer Epidemic: Modeling and Forecasts Based on Abortion and Other Risk Factors], by Patrick Carroll, MA. Published in the [[Journal of American Physicians and Surgeons]], Fall 2007. Accessed [[November 15]] [[2007]].</ref> a [[conservatism in the United States|politically conservative]] journal with a pro-life stance.<ref>"[http://www.aapsonline.org/resolutions/2003-2.htm 2003 Resolution - Affirming the Sanctity of Human Life]." A position statement from the [[Association of American Physicians and Surgeons]], publisher of the ''Journal of American Physicians and Surgeons''. Retrieved on [[November 15]], [[2007]].</ref> The study claimed that, among seven risk factors, abortion was the "best predictor of breast cancer," and fertility was also a useful predictor. It forecasts, for the year 2025, higher breast cancer rates for Czech Republic, England and Sweden and lower for Finland and Denmark based on abortion trends. Carroll's study was criticized by a [[The Guardian|Guardian]] editor, who alleged that the study's methodology was flawed and noted that it was funded by an anti-abortion group and published in a "right wing" journal.<ref>Brooks, Libby. "[http://www.guardian.co.uk/comment/story/0,,2192579,00.html British women's right to choose is under covert attack]." ''[[The Guardian]].'' [[October 12]], [[2007]]. Retrieved on [[November 19]], [[2007]].</ref>
==Criticism of media coverage==
In an article entitled "Blinded by Science" for the ''[[Columbia Journalism Review]]'', Chris Mooney argues that "balanced" coverage by the media of the ABC hypothesis, among other scientific hypotheses championed by the religious right, is an example of how the scientific fringe manipulates public opinion by insisting on the illusory notion of journalistic "balance" instead of scientific accuracy. In the article, Mooney criticizes [[John Carroll]] (former Editor-in-Chief of the ''[[Los Angeles Times]]'') for a rebuke Carroll made regarding an article written by Scott Gold about the ABC hypothesis for the ''L.A. Times''.<ref name="Gold">{{cite web |url=http://pqasb.pqarchiver.com/latimes/access/339453241.html?dids=339453241:339453241&FMT=ABS&FMTS=ABS:FT&type=current&date=May+22%2C+2003&author=Scott+Gold&pub=Los+Angeles+Times&edition=&startpage=A.1&desc=THE+NATION%3B+Texas+OKs+Disputed+Abortion+Legislation |title=THE NATION; Texas OKs Disputed Abortion Legislation |accessdate=2008-03-04 |format= |work=Los Angeles Times}}</ref> Gold's article covered the National Cancer Institute (NCI) workshop, and Carroll notes that when a scientific advocate ([[Joel Brind]]) for the ABC hypothesis is found:
<blockquote>
It is not until the last three paragraphs of the story that we finally surface a professor of biology and endocrinology who believes the abortion/cancer connection is valid. But do we quote him as to why he believes this? No. We quote his political views.
<p>
Apparently the scientific argument for the anti-abortion side is so absurd that we don't need to waste our readers' time with it.<ref name="Carroll memo">{{cite web |url=http://www.laobserved.com/carrollmemo.html |title=L.A. Observed: John Carroll memo |accessdate=2008-03-04 |format= |work=laobserved.com |author=John Carroll}}</ref>
</blockquote>
Carroll's concern is that Gold's article provides fodder to critics who claim that the ''L.A. Times'' has a liberal bias. Mooney writes in defense of Gold that:
<blockquote>
As a general rule, journalists should treat fringe scientific claims with considerable skepticism, and find out what major peer-reviewed papers or assessments have to say about them. Moreover, they should adhere to the principle that the more outlandish or dramatic the claim, the more skepticism it warrants. The Los Angeles Times’s Carroll observes that “every good journalist has a bit of a contrarian in his soul,” but it is precisely this impulse that can lead reporters astray. The fact is, nonscientist journalists can all too easily fall for scientific-sounding claims that they can’t adequately evaluate on their own.<ref name="mooney">{{cite web |url=http://cjrarchives.org/issues/2004/6/mooney-science.asp |title=CJR November/December 2004: Blinded by Science |accessdate=2007-12-24 |format= |author=Chris Mooney |work=Columbia Journalism Review}}</ref>
</blockquote>
Responding to criticism Carroll reiterated:
<blockquote>
You have an obligation to find a scientist, and if the scientist has something to say, then you can subject the scientist’s views to rigorous examination.<ref name="mooney"/>
</blockquote>
==References==
{{reflist|2}}
==External links==
* [http://cis.nci.nih.gov/fact/3_75.htm National Cancer Institute: Abortion, Miscarriage, and Breast Cancer Risk]
* [http://www.who.int/mediacentre/factsheets/fs240/en/index.html Induced abortion does not increase breast cancer risk], a fact sheet from the [[World Health Organization]]
* [http://www.cancer.org/docroot/CRI/content/CRI_2_6x_Can_Having_an_Abortion_Cause_or_Contribute_to_Breast_Cancer.asp American Cancer Society: Can Having an Abortion Cause or Contribute to Breast Cancer?]
* [http://www.acog.org/from_home/publications/press_releases/nr07-31-03-2.cfm American College of Obstetricians and Gynecologists: Finds No Link Between Abortion and Breast Cancer Risk]
* [http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1251638 Breast Cancer and the Politics of Abortion in the United States] by Dr. Patricia Jasen
'''Pro-choice:'''
* [http://www.plannedparenthood.org/issues-action/abortion/state-abortion-restrictions/reports/anti-choice-claims-about-abortion-breast-cancer-5095.htm Planned Parenthood: Anti-choice Claims About Abortion and Breast Cancer]
* [http://www.religioustolerance.org/abo_canc.htm Religious Tolerance: Is There A Link Between Abortion And Breast Cancer?]
* [http://www.crlp.org/pub_fac_brcancer.html Center for Reproductive Rights: False Claims of Breast Cancer Risk]
* [http://www.barryyeoman.com/articles/hatedabortion.html Discover Magazine: The Scientist Who Hated Abortion] by Barry Yeoman
'''Pro-life:'''
* [http://www.bcpinstitute.org/home.htm Breast Cancer Prevention Institute]
* [http://catholiccitizens.org/platform/platformview.asp?c=4654 CatholicCitizens.Org{{ndash}} The Scientific Debate That Never Happened]
* [http://www.abortionbreastcancer.com/ Coalition on Abortion/Breast Cancer]
* [http://www.johnkindley.com/weldonletter.htm JohnKindley.com]{{ndash}} Dr. Weldon's Dear Congress Letter
[[Category:Abortion debate]]
[[Category:Medical controversies]]