The latest issue of the Breast Cancer Prevention Institute’s (BCPI) newsletter reports that it often receives questions concerning the number of studies which show “a positive correlation or statistically significant results regarding induced abortion and breast cancer.”
Dr Angela Lafranchi, a breast cancer surgeon and President of BCPI, conducted a search of the literature to provide an answer to the question.
Her findings were that of the 66 studies done since 1957 to examine the link between abortion and breast cancer, there were 53 which “showed a positive correlation and 25 that were statistically significant.” 13 studies showed no association. Dr. Lafranchi points out that Louise Brinton, the author of one study,”had been a leader at at the 2003 National Cancer Institute workshop on Early reproductive Events and Breast Cancer risk which concluded that there was no association between breast cancer and induced abortion.” In 2009, she says , Louise Brinton, “has now reported that there is a 40% statistically significant  increase of breast cancer with induced abortion.”
Among other signicant studies on induced abortion and breast cancer, a sudy By Patrick Carroll published in 2007 in the American Journal of Physicians and Surgeons concluded that “induced abortion is found to be the best predictor” of breast cancer.
See the Breast Cancer Prevention Institute’s website for a complete list of epidemiological studies.