Risk of menopause during the first year after breast cancer diagnosis.

PURPOSE: Premenopausal women with breast cancer often enter a premature menopause during initial treatment of their malignancy, with resulting loss of childbearing capacity, onset of menopausal symptoms, and subsequent prolonged exposure to long-term risks of menopause. Adjuvant therapy is believed to contribute to this early menopause. PATIENTS AND METHODS: One hundred eighty-three premenopausal women with locoregional breast cancer (tumor-node-metastasis staging system classification, T1-3 N0-1 M0) who had undergone surgical treatment and provided information on menopausal status at diagnosis and 1 year later were enrolled. Systemic adjuvant therapy was recorded. Univariate and multivariate predictors of menopause were examined. RESULTS: Age, weight gain, tumor stage, nodal stage, and systemic adjuvant therapy (chemotherapy, tamoxifen) were all significant univariate correlates of menopause. In multivariate analysis, age, chemotherapy, and hormone therapy (tamoxifen) made significant independent contributions to the onset of menopause. CONCLUSION: Age and systemic chemotherapy are the strongest predictors of menopause in women with locoregional breast cancer. They independently contribute to menopause. A graphic representation of our multivariate model allows an estimation of risk of menopause according to patient age and planned adjuvant treatment, and it may facilitate clinical decision-making.