How Safe Are OCs and Menopausal Hormone Therapy After Breast Cancer?

The FDA considers a history of breast cancer a contraindication to use of all estrogens and progestins, including oral contraceptives (OCs) and hormone therapy. To determine whether OC or HT use increases risk for a second cancer in the contralateral breast, investigators from this multicenter, population-based, case-control study (funded by the NIH and the National Cancer Institute of Canada) compared 708 women with asynchronous bilateral breast cancer (cases) with 1399 women with unilateral breast cancer (controls).

All first cancers had not spread beyond regional lymph nodes at diagnosis. Second breast cancers were diagnosed at least 1 year after the first tumor diagnosis. Two controls were matched to each case by age and year of diagnosi…