Hyun-Ah Kim

Kim DG, et al. J Breast Cancer. 2026 ;29:e19. https://doi.org/10.4048/jbc.2026.0016

Ahn SG, et al. J Breast Cancer. 2026 Jan;29:e4. https://doi.org/10.4048/jbc.2025.0181

The addition of a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor to endocrine therapy augments biological response in breast cancer. This phase III randomized, double-blind study evaluated the efficacy of adding palbociclib to neoadjuvant endocrine therapy (NET) for operable, hormone receptor-positive human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Patients randomly received 16 weeks of endocrine therapy (letrozole for postmenopausal and tamoxifen plus ovarian function suppression for pre-/perimenopausal patients) plus palbociclib or placebo. The co-primary endpoints included preoperative endocrine prognostic index (PEPI) score and EndoPredict (EPclin) risk score according to the gatekeeping procedure. Of 141 randomized patients, 130 completed the treatment with surgical samples evaluable for endpoints in 126 patients. The proportion of patients with a low, moderate, and high PEPI score was 15.2, 50.0, and 34.8% in the palbociclib arm and 13.3, 55.0, and 31.7% in the placebo arm, respectively, with no statistical difference (one-sided P = 0.563). Statistical analysis was not performed on EPclin risk score. No new safety signals were reported. Permanent treatment discontinuation by adverse events was reported for seven (9.7%) and zero patients in the palbociclib and placebo arms, respectively. In conclusion, the addition of palbociclib to NET did not improve the efficacy. ClinicalTrials.gov NCT03969121.

Cha CD, et al. J Breast Cancer. 2024 Oct;27:e32. https://doi.org/10.4048/jbc.2024.0213

Background: While the relationship between mammographic breast density reduction (MDR) and endocrine therapy efficacy has been reported in estrogen receptor (ER)-positive breast cancer, it is still unclear in premenopausal women, especially in the case of adding ovarian function suppression (OFS) to antihormone therapy. The authors investigated the impact of MDR on prognosis stratified by treatment based on the updated results of the ASTRRA trial. Materials and methods: The ASTRRA trial, a randomized phase III study, showed that adding OFS to tamoxifen (TAM) improved survival in premenopausal women with estrogen receptor-positive breast cancer after chemotherapy. The authors updated survival outcomes and assessed mammography before treatment and the annual follow-up mammography for up to 5 years after treatment initiation. Mammographic density (MD) was classified into four categories based on the Breast Imaging-Reporting and Data System. MDR-positivity was defined as a downgrade in MD grade on follow-up mammography up to 2 years after randomization, with pretreatment MD grade as a reference. Results: The authors evaluated MDR in 944 of the 1282 patients from the trial, and 813 (86.2%) had grade III or IV MD. There was no difference in the MDR-positivity rate between the two treatment groups [TAM-only group (106/476 (22.3%)) vs. TAM+OFS group (89/468 (19.0%)); P=0.217). MDR-positivity was significantly associated with better disease-free survival (DFS) in the TAM+OFS group (estimated 8-year DFS: 93.1% in MDR-positive vs. 82.0% in MDR-negative patients; HR: 0.37; 95% CI: 0.16–0.85; P=0.019), but not in the TAM-only group (P _interaction=0.039). MDR-positive patients who received TAM+OFS had a favorable DFS compared to MDR-negative patients who received only TAM (HR: 0.30; 95% CI: 0.13–0.70; P=0.005). Conclusion: Although the proportion of MDR-positive patients was comparable between both treatment groups, MDR-positivity was independently associated with favorable outcomes only in the TAM+OFS group.

PURPOSE: 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. PATIENTS AND METHODS: 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). RESULTS: 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). CONCLUSION: 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.

Kim HJ, et al. Ann Surg Treat Res. 2023 Jul;105(1):1-9. https://doi.org/10.4174/astr.2023.105.1.1