Birth-Control Pills Increase Cancer Risks, Samuel Epstein, M.D.
Birth control pills increase cancer risks (Press Release 1/26/99)
Misleading Claims by an Industry-Sponsored Study on the Safety of the Pill
CHICAGO, Jan. 27 /PRNewswire/ -- The following was released today by Samuel S. Epstein, M.D., Professor of Environmental Medicine, University of Illinois School of Public Health:
A January 1999 study, funded by major international pharmaceutical companies, claims that oral contraceptives pose no risks of breast cancer or other ill effects. While the study was alleged to be the largest ever conducted, it was both small scale and insensitive. The study was based on 23,000 healthy women who had "never used" the pill since 1968 and who were subsequently followed up over a 25 year period. The average age of women at termination of the study was only 49, an age when breast cancer is relatively uncommon. Not surprisingly, the authors admitted that the number of breast and other cancers was so small that "further data is needed to confirm our findings".
In contrast, a 1996 large scale international collaborative analysis of some 54 epidemiological studies, based on over 53,000 women with breast cancer and published in The Lancet in1996, demonstrated that use of the pill starting in adolescence increased risks of breast cancer by 60 percent. These risks are clearly underestimates as reflected by the authors 'recognition that "there is little information about use that ceased more than 20 years ago", a latency much too short to preclude further major increases in breast cancer rates. Reliance on studies based on such short latencies would have exculpated the carcinogenicity of asbestos, besides the majority of other recognized human carcinogens. Other better designed and well controlled studies have reported much higher risks of breast cancer for women starting use of the pill in their teens or early twenties, especially with use before a full term pregnancy and subsequent prolonged use, and among women with a family history of breast cancer.
Moreover, the claim that the current low-dose synthetic ethinyl estradiol pill is much safer than the high-dose mestranol pill used in the 1960's and 1970's is misleading as the former is more potent than the latter, besides being some 40-fold more potent than natural estradiol; additionally, ethinyl estradiol, unlike mestranol, binds to estrogen receptors in the breast. Furthermore, the modern pill is used for much longer periods, often from menarche to menopause, than was the case with the earlier high-dose pills. It should further be emphasized that no studies have yet been conducted on the high potency modern pills and none are reportedly in progress. This is in striking contrast to the intensive investigation by Federal regulatory and health agencies on the endocrine-disruptive effects of estrogenic pesticides and other industrial contaminants whose potency is some 1/500,000th that of ethinyl estradiol.
Of related interest, it should be noted that the incidence of estrogen-dependent breast cancers, particularly among post-menopausal women, has increased by 130 per cent from the mid 70's in sharp contrast to only a 27 per cent increase in non-estrogen dependent cancers. This may well be relevant to the risks of the pill as a major source of incremental estrogen exposure.
Clearly, unqualified claims on the safety of the current pill reflect interests of the pharmaceutical industry rather than scientifically well-based concerns on women's health.
SOURCE: Cancer Prevention Coalition