Age and Menopausal Effects of Hormonal Birth Control and Hormone Replacement Therapy in Relation to Breast Cancer Risk

It is unclear whether breast cancer risk varies by age and menopausal status in relation to use of hormonal birth control (HBC) and hormone replacement therapy (HRT), taken singly or cumulatively. The authors utilized data from 1,478 cases and 1,493 controls aged 20–98 years with known menopausal status, who had participated in a population-based, case-control study conducted on Long Island during 1996–1997. Exogenous hormone use over the lifecourse was assessed by use of memory aids. The authors examined associations among women in these subgroups: premenopausal (n = 968), postmenopausal