Fighting breast cancer: Are we missing a major at-risk population?
Women are often urged to get screening mammograms even without having a family history of breast cancer because it is widely believed that 70% of women who get breast cancer have no known identifiable risk factors.
However, if findings from the published literature are carefully considered, reproductive history and exposure to estrogen1 can readily account for most of this 70%. One of these risks, termination of pregnancy (abortion), is almost never included in the list of risk factors despite the following data:
Epidemiological evidence linking breast cancer and abortion:
To date, 27 out of 35 studies worldwide show increased risk associated with induced abortion, 17 with statistical significance.2-36
To date, 13 out of 15 US Studies show increased risk, 8 with statistical significance.3-17
Strong correlations between breast cancer incidence and abortion exposure have been reported (e.g., in Washington State37, California34, Russia39, Sweden40 and Denmark41).
Endocrinologic basis for the breast cancer-abortion link:
Estrogens are the strongest known growth promoters of breast tissue and breast cancer tissue1,42.
Most breast cancer risk factors are attributable to some form of estrogen excess. That is why early menarche and late menopause are known to increase breast cancer risk43.
In pregnancy, maternal estrogen levels start rising before implantation44 and rise twenty-fold by the end of the first trimester, causing maximal proliferation of undifferentiated breast cells through the 2nd trimester45-46.
In the 3rd trimester, differentiation of breast cells makes them resistant to carcinogens. This is why full-term pregnancies lower breast cancer risk47.
Pregnancies that result in 1st trimester spontaneous abortion produce subnormal estrogen concentrations44-46,48, and generally do not increase breast cancer risk49. However, premature births before 32 weeks do more than double breast cancer risks50.
Pregnancies that result in induced abortion—without 3rd trimester differentiation—increase breast cancer risk49.
Experimental animal model data linking breast cancer and abortion:
Full-term pregnancy protects rats from chemical mammary tumor induction, but surgical abortion increases tumor incidence even beyond levels of virgin rats51.
- Developmental biology puts women who terminate their first pregnancy at even higher breast cancer risk:
Breast cells of nulligravidas show minimal differentiation and are thus maximally susceptible to carcinogens52.
- Family history puts women—especially young women—who terminate, at still higher breast cancer risk:
A 1994 study of almost 2,000 women in Washington State9 found that all twelve subjects who had aborted before age 18 and who had a positive family history—mother, sister, grandmother or aunt with breast cancer—were diagnosed with breast cancer by age 45!
- Why most clinicians have not been aware of the connection between abortion and breast cancer:
Most of the key studies connecting abortion to breast cancer have been published in journals not ordinarily read by clinicians, e.g., the International Journal of Epidemiology4, the Journal of Epidemiology and Community Health49 and the American Journal of Pathology51.
The abortion-breast cancer link goes against the common grain:
Many physicians believe abortion is a safe procedure, which saves women’s lives from the risk of a septic "back-alley" abortion53. Some of us believe that termination is safer than full-term delivery53. Naturally, data showing greater risk with abortion are viewed as suspect.
The National Cancer Institute (NCI) has disparaged the evidence of the abortion-breast cancer link54-56, despite clear, published refutations of their arguments41,42, and despite the fact that most NCI and NCI-funded studies have verified the abortion-breast cancer link. In fact, the central argument against the link rests on evidence which has since been retracted by its original proponents!57,58
Medical Societies; e.g., American College of Obstetricians and Gynecologists, do not support the data at their meetings.
Organizations such as the American Medical Women’s Association (AMWA ) are against efforts to require this information be given to women59.
However, the information, which is left out of most textbooks, is in the text, The Breast, by Bland & Copeland60.
Resistance to new ideas and new approaches is not unusual in our profession:
Data implicating Helicobacter pylori in peptic ulcer disease were ignored for over ten years before being acted upon, because it went against the common wisdom that hyperacidity was the cause of PUD.
In the treatment of breast cancer, surgeons believed in radical mastectomies based on the 100-year-old Halstead model until other investigators, who were prompted by women activists, looked at breast cancer in a new way, allowing partial mastectomies as a treatment.
MOST IMPORTANTLY, if we ignore this risk factor:
Women will not be screened properly; and therefore will be denied early breast cancer detection. Screening is known to increase survival by finding smaller, more differentiated breast cancers that are less likely to have metastatized61.
Women will not have the opportunity to decrease their risk of breast cancer after abortion by going through a pregnancy and breast feeding9.
Women will not have the opportunity to make informed choices and avoid the risk.
Parents will not be able to protect their children from this risk should they have an unplanned teenage pregnancy.
Women will not be considered for drug trials, such as the tamoxifen trials58, in an effort to find drug prophylaxis against breast cancer.
Further Information on the topics of abortion and breast cancer may be obtained from:
Angela Lanfranchi, MD, FACS at 732-356-0770 or Joel Brind, PhD at 914-463-3728 or
Breast Cancer Prevention Institute, 9 Vassar St., Poughkeepsie, NY 12601 at 1-866-622-6237 (Toll-free) or
The Coalition on Abortion/Breast Cancer via the internet at www.abortionbreastcancer.com
(References on reverse)
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