Random-start controlled ovarian hyperstimulation with letrozole for fertility preservation in cancer patients: case series and review of literature.

The aim of this case series was to describe our experience with random-start controlled ovarian hyperstimulation (RS-COH) with the use of letrozole for fertility preservation. GnRH antagonist and letrozole cycles were started in three patients with a diagnosis of cancer and had a limited time window for fertility preservation for COH before initiating cancer therapy. Cycles were started in the late follicular or luteal phase, and the duration of COH ranged between 7-8 days. A total of 4-14 oocytes were retrieved, the peak E2 levels were 252-354 pg/ml and the saved time for start of the cancer treatment were 16-26 days for each patient. In conclusion, RS-COH with letrozole cycle is a reasonable option for fertility preservation in cancer patients for whom the treatment window may be narrow. Also, the use of a letrozole for COH may decrease the potential risk of ovarian hyperstimulation syndrome.