Here's a bittersweet piece of news for anyone still heaving over last week's Supreme Court abortion decision: According to a study just published in the Archives of Internal Medicine (and reported on in the New York Times), having an abortion does not lead to an increased risk of breast cancer.
So what's with the fact that several states require abortion doctors to tell women they're putting themselves at a greater risk of breast cancer? Sure, it's an effective scare technique, but did it have a basis in actual research? Well, yes ... sort of. The assertion that an abortion puts you at greater risk of breast cancer comes from retrospective studies that looked backward at women diagnosed with breast cancer to see whether they'd had abortions in the past. The problem with such studies, the Times points out, is that they can lead to inaccurate self-reporting. "Healthy women may be reluctant to reveal that they have had an abortion," says the Times, "while those with breast cancer, seeking a cause for their illness, are more likely to report one."
This new study was prospective, which means that it looked into the future. It analyzed whether women who had had abortions later developed breast cancer at higher rates than their counterparts who had full-term pregnancies. Started in 1993, it followed 105,716 women, a little under a third of whom had had either induced or spontaneous abortions. Researchers also kept track of their subjects' breast cancer risk factors, starting from 1989. At the end of the study, they concluded that having an abortion, induced or noninduced, had no impact on the women's chances of developing breast cancer.
Of course, as is true with any medical study, there are criticisms. One doctor interviewed by the Times suggested that the researchers should have looked only at abortions that happened early in the study (as opposed to counting abortions that happened after the study had begun) to make sure there was enough time for breast cancer to have had a chance to develop. (The researchers refute this, saying that most of the abortions in the study happened at least 10 years before its end, and that even when they analyzed only the women who had abortions in the very beginning of the study, the results remained the same.)
Another criticism is that the study doesn't take into account the well-established evidence that a full-term pregnancy before age 35 confers long-term protection against breast cancer. In other words, having an abortion itself might not put you at higher risk of cancer, but you could be missing out on the benefits you would have accrued had you given birth. But Karin Michels, the study's lead author, is quoted as saying that they did "'analyze the data keeping this issue in mind ... and did not find that an incomplete pregnancy deprives a woman of the protection a full-term pregnancy would have conferred.'"
Let's hope people keep this study in mind when, as the Times suggests may happen, cases go to court arguing that abortion procedures can be banned if they pose a risk to women's health.