Safety and feasibility of performing two consecutive ovarian stimulation cycles with the use of letrozole-gonadotropin protocol for fertility preservation in breast cancer patients.

To investigate the safety and feasibility of performing two consecutive ovarian stimulation cycles with the use of letrozole protocol for fertility preservation in breast cancer patients. Retrospective cohort study. Academic fertility preservation center. Seventy-eight women ≤ 45 years, diagnosed with stage ≤ 3 breast cancer, who desired fertility preservation. Two consecutive cycles versus a single ovarian stimulation cycle with a letrozole-follicle-stimulating hormone (FSH) protocol. Embryo or oocyte cryopreservation outcomes, time interval from surgery to chemotherapy, and breast cancer recurrence rates. Sixty-one patients underwent single-cycle stimulation and 17 received two stimulation cycles. The mean total number of oocytes harvested (16.1 ± 13.2 vs. 9.1 ± 5.2) and embryos generated (6.4 ± 2.9 vs. 3.7 ± 3.1) were statistically significantly higher in patients who underwent two cycles versus one cycle. The time interval from surgery to chemotherapy was similar between the two-cycle and single-cycle groups (63.7 ± 7.7 vs. 58.0 ± 12.1 days). After a mean follow-up interval of 58.5 ± 13.6 months, the recurrence rates were similar between the two-cycle (0 of 17) and single-cycle (2 of 49) patients. It appears to be safe and feasible to perform two consecutive ovarian stimulation cycles to increase the oocyte/embryo yield for fertility preservation.