Related Experiment Video
Updated: Jul 6, 2026
Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
Oncologic Safety of Preoperative Controlled Ovarian Stimulation for Fertility Preservation Among Women with Estrogen
Jennifer H Chen1, Irene Peregrin-Alvarez2,3, Carla L Warneke4
1Department of Breast Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Background:
The oncologic safety of preoperative controlled ovarian stimulation (COS) for fertility preservation in women with an in situ estrogen receptor positive (ER+) breast cancer is unclear. The purpose of this study was to compare oncologic outcomes of women with ER+ breast cancer undergoing preoperative COS versus (1) postoperative COS or (2) matched controls not undergoing COS.
Patients And Methods:
This was a single-institution retrospective cohort study of women with ER+ breast cancer receiving oncofertility counseling who pursued COS from 2014-2024. The primary outcome was progression-free survival (PFS). A subcohort of patients who received neoadjuvant systemic therapy was compared with a matched cohort of similar patients with ER+ breast cancer who did not undergo COS. Propensity score matching criteria were age, HER2 receptor status, and clinical stage.
Results:
Among 51 women with ER+ breast cancer undergoing COS, the median follow-up was 5.5 years. 5-year PFS was similar for preoperative COS (n = 32) versus postoperative COS (n = 19): 94.1% (95% CI 65.0-99.2%) versus 93.3% (95% CI 61.3-99.0%), p = 0.73. Patients undergoing neoadjuvant systemic therapy (NST) and preoperative COS (n = 30) experienced a significantly longer time from diagnosis to NST initiation than propensity-score matches who did not undergo COS (48 versus 29.5 days, p < 0.0001), but disease-free survival was similar: 94.1% (95% CI 65.0-99.2%) versus 93.3% (95% CI 75.9-98.3%), p = 0.15.
Conclusions:
In this study of women with ER+ breast cancers, preoperative COS was not associated with increased risks of disease progression or death. While COS was associated with a modest delay in NST initiation, PFS was similar to propensity-score matched patients who did not undergo COS. Results support the oncologic safety of COS in the setting of an in situ ER+ tumor and provide much-needed evidence for young women with breast cancer receiving gonadotoxic NST who desire future childbearing during survivorship.
