But the idea is appealing, especially among those who viewed a perceived "epidemic" of breast cancer among young, sexually-active women as a punitive result of the Roe v. Wade decision. In fact, as Patricia Jasen explains in a survey of the political and historical context of the ABC link research, that initial observation of an increased rate of breast cancer among American women is likely due to more sophisticated early detection methods that coincidentally gained traction during the post Roe v. Wade period.
This is the context of today's advocacy on the ABC theory. A handful of scientists, such as Joel Brind, a professor of biology and endocrinology at Baruch College in New York, have dedicated their careers to finding ways to prove the link. Brind worked hard to promote the recent Chinese study, claiming that the only reason the ABC link hasn't caught on is because of a vast conspiracy to suppress it. The groups working against the theory, he writes, include:
"'mainstream' abortion advocates entrenched in universities, medical societies, breast cancer charities, journals, and especially, government agencies like the National Cancer Institute (In reality, the NCI is just another corrupt federal agency like the IRS and the NSA.)."
The recent study is not by Brind himself, but by Dr. Yubei Huang et al., whose meta-analysis of 36 Chinese studies concludes that induced abortions increase the risk of breast cancer by 44 percent. For women who have had two abortions, the study claims an increased risk of 76 percent. Those are dramatic numbers. So, what's going on?
Most of the studies use a notoriously misleading method
"The findings of this meta-analysis should be viewed with caution," Dr. Susan Gapstur told The Wire in an email. Gapstur is the vice president of epidemiology at the American Cancer Society. She notes that almost all of the studies cited in Dr. Huang's analysis used something called the case-control method, which tends to produce misleading results. In the case of the abortion-breast cancer link, women with breast cancer who self-report their reproductive histories tend to do so more accurately than women who are cancer-free. And in countries like China, where abortion still carries a significant stigma, that "recall bias" can be reinforced. "This 'recall bias' can make it look like breast cancer is associated with abortion when it is not," Gapstur explains. Case-control methods, it should be noted, have produced links between breast cancer and induced abortion before.
The best studies of the bunch found no link
All but two of the studies included in Huang's analysis used the case-control method. The remaining two were prospective cohort studies, which track women over time, instead of relying on self-reported historical results. Those two studies, Gapstur notes, did not find a link between abortion and breast cancer. In fact, the eight studies that appear to be the most reliable of the group found no link between induced abortion and breast cancer risk. "The association only became apparent as the quality of the studies decreased," Gapstur told The Wire, noting that some of the included studies were not published in peer-reviewed publications. In other words, the work might not be vetted by independent professionals in the field.