Planned Parenthood's funding cut: Does science support abortion-cancer link?

The Susan G. Komen for the Cure Foundation decided to pull its funding this week from Planned Parenthood, claiming the cutoff was a result of Planned Parenthood’s new policy barring grants to organizations under investigation by local, state or federal authorities, but another non-profit group has posed a new theory.

Pro-life group American Right to Life (ARTL) thinks Komen’s motive has to do with a link between abortions and breast cancer.

“We suspect the real reasons is the growing evidence that abortion significantly increases the incidence of breast cancer,” Lolita Hanks, nurse practitioner and president of ARTL, said in a press release.

“Now that the lead National Cancer Institute [NCI] researcher on the abortion/cancer link has reversed herself and warned of abortion as a significant risk factor for breast cancer, the pro-life pressure on Planned Parenthood and Susan G. Komen is increasing.”

But is ARTL’s theory supported by science?

Dr. Louise Brinton, the NCI researcher mentioned by Hanks, declined to comment to FoxNews.com.

But representatives from NCI told FoxNews.com that the materials on their website reflect their official stance on the matter.  According to their online article about ‘Abortion, Miscarriage, and Breast Cancer Risk,’ the institute refutes the claims made by Hanks and ARTL, saying that “the evidence overall still does not support early termination of pregnancy as a cause of breast cancer.”

And at least one breast surgeon agrees.

Dr. Rachel Wellner, director of breast services at NYEE, Continuum Cancer Center in New York City, said the studies that have examined a possible link between induced or spontaneous abortion and increased risk in breast cancer are inadequate.

“The research that's been done is not prospective; it's all retrospective,” Wellner told FoxNews.com.  “They looked and reviewed cases that all happened in the past.  These data may reflect some sort of trend, but its retrospective design is inherently limited.”

In order to accurately test for a link between abortion and breast cancer, researchers would need to accumulate a group of pregnant women who were undergoing abortions, along with a control group of women who did not undergo abortions, and then study them over a lengthy period of time to see how many of them eventually developed breast cancer.

And most importantly, the researchers would have to control for certain factors that may influence the results such as genetics, age, environmental exposures and other reproductive factors.

However, the likelihood of such research to ever take place isn’t very high, according to Wellner.

“That study would be very hard to accrue,” Wellner said.  “I would imagine it would be very difficult to find women undergoing an abortion who would then want to participate in a breast cancer study.”

While the chances of accurately establishing a link between abortion and breast cancer may be slim, Wellner does acknowledge the possibility that a link may exist and why some may be concerned.

“From a scientific perspective, pregnancy does change the breast physiology,” Wellner said.  “But this is true for any sentinel event in a woman’s hormonal life, such as puberty, pregnancy, lactation, menopause, etc.  So presumably when you stop a pregnancy through abortion, there may be a hormonal change.”

Wellner also added that other studies involving completed pregnancies may indicate that an aborted pregnancy may have some effect on the health of a woman’s breast.

“We know that experiencing pregnancy to its completion appears to be protective against breast cancer, Wellner said.  “We also know that nulliparity (having no children) or a late onset of a first pregnancy puts women at slightly higher risk of developing breast cancer versus their counterparts who experienced earlier pregnancies.  So presumably the changes experienced in an induced abortion may invoke cellular changes that promote risk.  So it does make some sense.”

No matter the speculation, Wellner maintained that with the evidence currently on file, there is not enough to conclude a link, and most likely, there never will be definitive data.

“In the absence of prospective trials, we can only rely on trends,” she said.