Bethesda, Md., Jan 7, 2010 / 07:40 am (CNA).- An April 2009 study co-authored by a researcher who has previously denied an abortion-breast cancer link shows a statistically significant increase in breast cancer risk among women who have had abortions or who use oral contraceptives. The study by researchers including Jessica Dolle of the Fred Hutchinson Cancer Research contained a table reporting a statistically significant 40 percent risk increase for women who have had abortions. According to the Coalition on Abortion/Breast Cancer (CABC), the study listed abortion as among “known and suspected risk factors.”
The CABC says that one co-author of the study, U.S. National Cancer Institute (NCI) researcher Dr. Louise Brinton, had organized a 2003 NCI workshop on the abortion-breast cancer link. That workshop reportedly said the non-existence of an abortion-breast cancer link was “well established.”
CNA contacted Dr. Brinton for comment but did not receive a reply by publication time.
Dr. Joel Brind, who is a CBCP advisor and president of the Breast Cancer Prevention Institute and a professor of endocrinology at Baruch College at City University of New York, said that the study’s findings on abortion were not new.
Rather, they repeated the “modest but significant” findings of the 1990s which found a breast cancer risk factor increase of between 20 and 50 percent.
However, he said Dr. Brinton’s participation in the study was significant because the NCI has “firmly maintained” a position denying an abortion-breast cancer link since 2003.
The study, titled “Risk factors for triple-negative breast cancer in women under the age of 45 years,” was published in the American Association for Cancer Research’s (AACR) medical journal “Cancer Epidemiology, Biomarkers and Prevention.”
Researchers also found a significant link between the use of oral contraceptives and a particularly aggressive cancer known as triple-negative breast cancer (TNBC).
Brind said that according to the study, women who start oral contraceptives before the age of 18 multiply their risk of TNBC by 3.7 times. Those who were users of oral contraceptives within one to five years before the study showed a risk 4.2 times the average.
TNBC is associated with high mortality. Brind suggested that oral contraceptives may function not merely as a secondary carcinogen. Rather, the synthetic estrogen-progestin combination or its metabolic byproducts may be a primary cause of the cell mutations that lead to cancer formation.
CBCP president Karen Malec criticized that the NCI, the American Cancer Society, Susan G. Komen for the Cure and other cancer organizations for not issuing nationwide warnings to women on the basis of the study.