DOI: 10.1200/jco.23.00557 ISSN:

Adding Ovarian Suppression to Tamoxifen for Premenopausal Women With Hormone Receptor–Positive Breast Cancer After Chemotherapy: An 8-Year Follow-Up of the ASTRRA Trial

Soo Yeon Baek, Woo Chul Noh, Sei-Hyun Ahn, Hyun-Ah Kim, Jai Min Ryu, Seung Il Kim, Eun-Gyeong Lee, Seock-Ah Im, Yongsik Jung, Min Ho Park, Kyong Hwa Park, Su Hwan Kang, Joon Jeong, Eunhwa Park, Sung Yong Kim, Min Hyuk Lee, Lee Su Kim, Woosung Lim, Seonok Kim, Hee Jeong Kim
  • Cancer Research
  • Oncology


To determine the updated long-term outcomes of the Addition of Ovarian Suppression to Tamoxifen in Young Women With Hormone-Sensitive Breast Cancer Who Remain Premenopausal or Regain Vaginal Bleeding After Chemotherapy (ASTRRA) trial.


This study is a post-trial follow-up of the ASTRRA trial, involving 1,483 premenopausal women younger than 45 years treated with definitive surgery after completing adjuvant or neoadjuvant chemotherapy for estrogen receptor–positive breast cancer. Patients were randomly assigned in a 1:1 ratio to complete 5 years of tamoxifen (TAM) alone (TAM-only) or 5 years of TAM with ovarian function suppression (OFS) for 2 years (TAM + OFS). The primary end point was disease-free survival (DFS), and the secondary end point was overall survival (OS).


At 106.4 months of median follow-up, there was a continuous significant reduction in the DFS event rate in the TAM + OFS group. The 8-year DFS rate was 85.4% in the TAM + OFS group and 80.2% in the TAM-only group (hazard ratio [HR], 0.67; 95% CI, 0.51 to 0.87). There were no significant differences in OS between the two groups. The OS rate was 96.5% in the TAM + OFS group and 95.3% in the TAM-only group (HR, 0.78; 95% CI, 0.49 to 1.25).


Adding OFS for 2 years to adjuvant TAM with a longer follow-up resulted in consistent DFS benefits, suggesting that adding OFS to TAM should be considered for patients who remain in a premenopausal state or resume ovarian function after chemotherapy.

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