Replies

Here is the link: pregnancy or anything else that reduces the number of fertile cycles a woman goes through in her lifetime (including late onset of menses, early menopause, breastfeeding, having a hysterectomy at a young age) reduces a woman's chance of getting breast cancer. So on the one hand, the women statistically less likely to get breast cancer are those who have had many children and breastfed them for significant periods of time. On the other hand, the women statistically more likely to develop breast cancer are those who have never been pregnant. It's a continuum. Anything that moves you from farther up on the continuum to farther down toward the never-been-pregnant state moves you (speaking statistically for a large group of women) closer toward getting breast cancer. Abortion, by causing a pregnancy to cease early, would move a woman away from the more protective effect of having had a full term pregnancy and toward the less protection of never having been pregnant. What it does not do is to subject a woman to a higher risk of breast cancer than a woman who has never become pregnant at all.

Another important thing to keep in mind is that the studies that show some increase in risk show a very slight increase in relative risk. In these studies, the increase in relative risk from, say, 0.7 to 1.4 doesn't mean that you are now twice as likely to get breast cancer (though this is how it's being reported) because you have to have an increase in relative risk well beyond 2 for there even to be a certainty of a correlation that that exceeds background noise. Even then, the correlation is not a measure of cause and effect between the two events which are correlated.

However, the more recent, very large and better-controlled studies have shown abortion either to have no effect on breast cancer rates or a slightly protective effect. This isn't to say that abortions are negligible or good. But it does underscore the way people are trying to push a particular social program by describing data in a deceptive way because they think the end justifies the means. All they will do, though, eventually is to discredit their overall message while undermining confidence in science because they've subordinated it to propaganda.