Chemotherapy-induced ovarian toxicity in patients affected by endocrine-responsive early breast cancer

Cytotoxic chemotherapy may variably affect ovarian function depending on age and ovarian reserve at diagnosis, type of chemotherapy and use of tamoxifen. Ascertaining whether a premenopausal patient with endocrine-responsive early breast cancer and chemotherapy-induced amenorrhea has reached menopause is essential not only in order to provide accurate information on residual fertility, but also to appropriately prescribe endocrine therapy. Indeed, aromatase inhibitors are contraindicated in women with residual ovarian reserve. However, the diagnosis of menopause in patients with chemotherapy-induced amenorrhea is challenging, since clinical features, follicle-stimulating hormone and estradiol levels may be inaccurate to this aim. Recent studies demonstrated that the anti-mullerian hormone may improve the assessment of ovarian reserve residual to chemotherapy in women with early breast cancer. Herein, we review the incidence of amenorrhea and menopause induced by cytotoxic chemotherapy in women affected by early breast cancer and the suggested mechanisms that sustain these side-effects. Furthermore, it has been scrutinized the potential of new markers of ovarian reserve that may facilitate the selection of appropriate endocrine treatment for premenopausal women who develop amenorrhea following adjuvant chemotherapy for early breast cancer.