Do fertility drugs affect a woman’s risk of developing breast cancer? A new study suggests that the risk hinges on whether they actually help a woman get pregnant.
Scientists have been concerned about the effects of fertility drugs in recent years, citing a possible relationship between the hormones altered by the drugs and those implicated in breast cancer. Studies attempting to pinpoint the link between fertility drugs and cancer risk have varied widely in their conclusions. Some have found a reduction in cancer risk, some an increased risk. Others found no connection at all.
But researchers at the National Institutes of Health found that although the drugs seem to reduce breast cancer risk in young women, the risk goes up when they get pregnant.
Researchers studied pairs of sisters, in total following more than 1,400 women who had been diagnosed with breast cancer before age 50 and more than 1,600 of their sisters who had never had breast cancer. Of these women, 288 reported using ovulation-stimulating fertility drugs, clomiphene citrate and follicle-stimulating hormone, at some point; 141 women reported a pregnancy lasting 10 weeks or more after taking the drugs.
