Baseline bone mineral density (BMD) testing and fracture risk assessment is recommended for patients with primary breast cancer for whom therapy with agents that suppress ovarian function is given, including premenopausal women with premature ovarian failure or ovarian suppression with luteinizing hormone releasing hormone analogue (LHRHA) and postmenopausal women on aromatase inhibitors (AIs). The gene discussed is CYP19A1; the disease is breast carcinoma.