Fertility stimulation protocols in women with cancer.

All female oncology patients undergoing controlled ovarian stimulation for fertility cryopreservation should be offered an antagonist protocol. Therapy can begin at the time of the first visit, providing consent is obtained. There is no need to delay until the next period. Stimulated patients should be monitored with ultrasound and estradiol levels as per normal clinic practice. For women with a diagnosis of breast cancer, and with the agreement of the treating oncologist, the stimulation protocol should include an aromatase inhibitor such as letrozole to reduce the circulating estradiol levels. All patients should have a gonadotropin-releasing hormone trigger to eliminate the risk of ovarian hyperstimulation syndrome and facilitate timely return for cancer therapy.