Marklund A, Eloranta S, Wikander I, et al. - Researchers examined the efficacy and safety of the current approaches to controlled ovarian stimulation (COS) aimed at fertility preservation (FP) in women with breast cancer (BC). They conducted a prospective multicenter study with national coverage including 610 women with BC counseled between January 1, 1995 and June 30, 2017 at six Swedish FP regional programs. Four hundred and one women elected to undergo COS after counseling. Differences were evident between treatments in the use or not of concomitant letrozole, a conventional or random-cycle day COS initiation and the use of hCG vs GnRHa trigger for oocyte maturation. Outcomes revealed equal effectiveness of letrozole-based protocols and those randomly started when compared with conventional COS among women with BC undergoing COS aiming at egg/embryo cryopreservation; women that proceeded to FP and those who did not were similar regarding the overall survival.