In this Oct. 16, 2010 file photo, some of an estimated 45,000 people participate in the Susan B. Komen Race for the Cure in Little Rock, Ark. The nation's leading breast-cancer charity, Susan G. Komen for the Cure, is halting its partnerships with Planned Parenthood affiliates in 2012. (Brian Chilson/Associated Press)

But long before that decision was announced, some people questioned that funding arrangement for slightly different reasons. The Coalition on Abortion/Breast Cancer, for instance, has long claimed that abortion increases breast cancer risk and therefore an organization whose mission is to battle breast cancer should not support an organization whose activities include providing abortions. Similar questions have been raised about the potential link between use of oral contraceptives (which are available through Planned Parenthood) and breast-cancer risk.

Those arguments may be a thin veil for underlying political, moral and religious concerns. But the science regarding the potential link between abortion and breast-cancer risk has been spotty, mostly because of the difficulties in designing studies to test the relationship. As recently as November 2011, research has suggested there may be a rise in breast cancer risk among women who have had an abortion.

But the bulk of evidence appears to argue against abortion’s causing breast cancer. That’s according to the American Cancer Society and the National Cancer Institute, which offer overviews of existing research and conclusions scientists have come to after examining those studies. While research suggests a slight increased risk of breast cancer among women currently using oral contraceptives, that’s not the case with abortion and breast cancer risk. As the American Cancer Society’s Web site concludes: “Linking these 2 topics creates a great deal of emotion and debate. But scientific research studies have not found a cause-and-effect relationship between abortion and breast cancer.”

Komen’s decision to stop funding Planned Parenthood will certainly revive this debate.