MONDAY, March 3, 2003 (HealthDayNews) -- Having an abortion does not increase a woman's risk of breast cancer, contrary to previous studies, a panel of scientists convened by the National Cancer Institute (NCI) concludes.
Their report will be presented March 3 to the NCI's board of scientific advisors and counselors, which will then issue a final recommendation.
The Early Reproductive Events and Breast Cancer Workshop was convened last week by NCI Director Dr. Andrew von Eschenbach to present and review information on the risk of breast cancer associated with pregnancy. Scientific studies have yielded mixed findings. The fact sheet currently posted at the NCI Web site states that some studies have reported evidence of increased breast cancer risk in women who have had abortions, while others have found no increase in risk.
The debate is politically charged, with some anti-abortion groups using the data that says abortion boosts breast cancer risk to persuade women not to abort.
At the recent workshop, the experts "reviewed data on early reproductive events and breast cancer risk, and examined the existing and new data [some of it still to be published or in press] from epidemiologic studies, mechanistic studies and animal studies on all aspects of pregnancy," says Leslie Bernstein, a professor of preventive medicine at the Keck School of Medicine of the University of Southern California. Bernstein, a member of the panel, will present the findings to the NCI.
"The participants created a list of scientific findings, gaps in the science, and proposed future research," she says. All of this will be considered by the NCI boards before the final recommendation is issued.
The studies that did find a link between breast cancer risk and induced abortion had problems, such as underreporting by subjects or numbers too small to be scientifically sound, Bernstein says.
Not everyone agreed with the conclusion. One workshop participant, Joel Brind, a professor from the City University of New York, objected. For more than a decade, he has written and lectured on the association between abortion and breast cancer risk. "He does interpret all of the data differently," Bernstein says.
Brind did not answer a telephone request for an interview.
Exactly how an abortion was linked in previous studies to increased breast cancer risk -- and why a full-term pregnancy protects against cancer, as believed -- is not fully understood, Bernstein says. "Previously, the hypothesis put forth has been that it leads to complete differentiation of the breast tissue, which is true, but that may not be the reason for protection." Now, scientists believe other mechanisms may act during pregnancy to protect against breast cancer, and may act early in pregnancy.
The scientists also addressed other issues, including the finding that miscarriage does not boost risk of breast cancer, either.
Not everyone thinks the workshop was necessary.
"The conclusion is confirmation that we didn't need this conference," says Barbara A. Brenner, executive director of Breast Cancer Action, a national grassroots advocacy organization based in San Francisco. She says the impetus for the conference was to advance "a right-wing agenda" from some who hoped the conclusion would be different.
Whatever the final recommendation of the NCI, some say the debate probably isn't over. "The anti-abortion [organizations] will never let this die," Brenner says.
More information
To see the government's current fact sheet addressing early reproductive events and breast cancer, click on the National Cancer Institute. To learn more about the disease in general, visit the American Cancer Society.
