Since our hospital is an integrated Regional Reference Center in the osteoporosis prevention and treatment network, a high percentage of patients (38.4%) had a history of hormone-sensitive cancer and were on adjuvant hormone treatment (aromatase inhibitors and LH-RH analogs for breast cancer and LH-RH analogs and 5α-reductase inhibitors for prostate cancer). This evidence concerns the gene CYP19A1 and breast cancer.