The worries were well founded. Breast cells proliferate during the early stages of pregnancy, becoming more prone to malignancy. Abortion interferes with subsequent hormonal changes that make the cells less vulnerable. The concern escalated last fall, when researchers at Penn State University and Baruch College in New York pooled results from 23 studies and found that abortion increased breast-cancer risk by nearly a third. Many of the studies in that analysis had relied on women to recount their own abortion histories. The new study, led by Dr. Mads Melbye of the Danish Epidemiology Science Center, drew data directly from national registries of births, abortions and cancer cases.
Among the 1.5 million women in the study, roughly 281,000 had undergone abortions, and 10,000 had developed breast cancer. But those who had terminated pregnancies were no more tumor-prone than those who hadn’t. Future studies, which follow women over longer periods, may yet reveal patterns that this one missed. Until then, consider the case closed.
