Incidence of chemotherapy-induced ovarian failure in premenopausal women undergoing chemotherapy for breast cancer.

Introduction: Breast cancer is increasingly reported in young premenopausal women in Asia. Adjuvant chemotherapy improves survival; however, it has a unique consequence of ovarian failure in premenopausal patients.
Objective: This study's aim was to find the incidence of chemotherapy-induced ovarian failure (CIOF) and reversible amenorrhea in premenopausal non-metastatic breast cancer patients.
Method: This mixed retrospective and prospective study follows premenopausal breast cancer patients receiving chemotherapy between 2008 and 2012. Patients in the prospective arm were followed up with menstrual history and serum ovarian hormones (follicle-stimulating hormone [FSH] and estradiol) until 1 year post-chemotherapy, and patients in the retrospective arm were contacted for their menstrual history.
Results: The mean age of the 102 subjects was 43.3 years. Of the patients, 93.1 and 77.9 % were amenorrheic at completion of chemotherapy and at 12 months post-chemotherapy, respectively. Of those who developed amenorrhea, 24.6 % regained menstruation, on average after 7.86 (range 1-15) months post-chemotherapy. Age was the only statistically significant risk factor. CIOF and reversible amenorrhea was 57 and 50 % at <35 years, 95 and 31.6 % at 35-45 years, and 97.9 and 14.9 % at >50 years, respectively. The 33 prospective patients' estradiol and FSH levels seem to correlate well with onset of amenorrhea, with a falling estradiol and rising FSH trend. Tamoxifen use was associated with elevated estradiol levels 1 year post-chemotherapy.
Conclusion: This study found a high incidence of CIOF, with a relatively low rate of reversible amenorrhea. Premenopausal patients should be counselled prior to treatment and education and support provided.