RESUMO
BACKGROUND: Premenopausal patients treated with adjuvant chemotherapy often develop early menopause and thus, may encounter significant bone loss. We studied the long-term effects of chemotherapy-induced ovarian dysfunction on bone mineral density in breast cancer patients. MATERIAL AND METHODS: The effect of menstrual status after adjuvant chemotherapy on bone mineral density (BMD) was examined in 29 premenopausal breast cancer patients. RESULTS: During 10 years of follow-up, nearly 90% of women developed menstrual irregularities or amenorrhea. The total bone loss at the lumbar spine was -5.4% in women with preserved menstruation, -15.3% in those with irregular menses and -13.2% in amenorrheic women 10 years after adjuvant chemotherapy. The changes in lumbar spine BMD correlated significantly with menstrual function. Both amenorrhea and menstrual irregularities shortly after chemotherapy increased the risk of osteoporosis later on: one third of women with ovarian dysfunction developed osteoporosis of the lumbar spine during the follow-up. Osteopenia before adjuvant therapy predicted an increased risk for osteoporosis. CONCLUSION: The present study with a unique follow-up period of 10 years shows that ovarian dysfunction leads to long-term deleterious BMD changes and predisposes breast cancer survivors to osteoporosis.