Ovarian ablation or suppression is associated with a lower risk of breast cancer recurrence and death in premenopausal women with estrogen receptor (ER)-positive breast cancer, a meta-analysis suggests. 

These findings were presented at the ASCO Annual Meeting 2023 by Richard G. Gray, of the University of Oxford in the UK.

The meta-analysis included 14,999 patients from 23 trials who were premenopausal at randomization. Gray noted that many of these patients had received chemotherapy after randomization and would have been susceptible to becoming menopausal, but their menopausal status after chemotherapy was unknown. 

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Because of this limitation, the trials were separated into 2 groups: 

  • Trials that involved no chemotherapy (12 trials, 3934 patients) or trials with chemotherapy given before randomization and with patients’ premenopausal status confirmed after (2 trials, 3279 patients)
  • Trials with post-randomization chemotherapy that could have induced menopause (14 trials [5 of these also contributed to the first group], 7786 patients). 

Among patients who did not receive chemotherapy or who were known to be premenopausal after chemotherapy, the rate of breast cancer recurrence at 15 years was 29.5% in those who were treated with ovarian ablation/suppression and 39.3% in those who were not (rate ratio [RR], 0.71; P <.00001). 

Not receiving tamoxifen was associated with a greater reduction in recurrence for patients who had ovarian ablation/suppression. 

Among patients who were premenopausal before chemotherapy but had uncertain status after, the rate of recurrence at 15 years was 43.1% in those who received ovarian ablation/suppression and 44.4% in the control group (RR, 0.91; P =.02). 

Among patients who did not receive chemotherapy or who were known to be premenopausal after chemotherapy, the rate of breast cancer death at 20 years was 23.8% in those who had ovarian ablation/suppression and 34.7% in the control group (RR, 0.71; P <.00001). 

The rate of death without recurrence at 20 years in the chemotherapy-free/premenopausal cohort was 9.3% in the ovarian ablation/suppression group and 11.5% in the control group (RR, 0.89; P =.36). The rate of all-cause mortality at 20 years was 30.4% and 42.0%, respectively (RR, 0.75; P <.00001).

Gray concluded that this meta-analysis showed a “substantial and persistent benefit” from ovarian suppression or ablation in premenopausal patients with ER-positive breast cancer. 

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Gray RG, Bradley R, Braybrooke J, et al. Effects of ovarian ablation or suppression on breast cancer recurrence and survival: Patient-level meta-analysis of 14,993 pre-menopausal women in 25 randomized trials. ASCO 2023. June 2-6, 2023. Abstract 503.