Does higher starting dose of FSH stimulation with letrozole improve fertility preservation outcomes in women with breast cancer?

OBJECTIVE

To evaluate the efficacy of ovarian stimulation with higher doses of gonadotropins in fertility preservation (FP) cycles with the intention to maximize the likelihood of future pregnancies.

DESIGN

Retrospective (secondary analysis).

SETTING

Academic medical centers.

PATIENT(S): Low-dose (LD, 150 IU; n = 34) versus high-dose (HD, >150 IU; n = 117) FSH start in 151 patients with breast cancer (BCa) undergoing ovarian stimulation for embryo cryopreservation with letrozole (LE) before cancer treatment.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): FP cycle outcomes.

RESULT(S): Mean total FSH dose (2,037 ± 679 IU vs. 1,128 ± 381 IU) and FSH level on trigger day (21.1 ± 8.9 vs. 10.6 ± 4.5 mIU/mL) were higher in the HD group, confirming the receipt of higher-dose FSH. There was no difference in other patient characteristics. Despite the larger number of follicles >17 mm in diameter in the HD group (5.0 ± 2.0 vs. 3.4 ± 1.4), neither peak E(2) (498.0 ± 377.5 vs. 397.9 ± 320.3), number of oocytes (13.3 ± 8.7 vs. 12.3 ± 8.0), nor number of embryos (6.3 ± 4.7 vs. 5.4 ± 3.8) were significantly different from the LD group. Of those undergoing frozen embryo transfer (ET), live birth rate (LBR)/ET trended higher in the LD (9/15) compared with HD (2/11) group, with 2.1 ± 0.8 vs. 1.9 ± 0.3 embryos transferred, respectively.

CONCLUSION(S): Higher-dose FSH stimulation in LE cycles does not improve outcomes and may be associated with lower LBR. Our findings may support minimal stimulation in young noninfertile women with BCa.