Clinical response and prognosis of estrogen receptor-positive and human epidermal growth factor receptor-negative breast cancer patients after neoadjuvant chemotherapy: a retrospective cohort study
10.4174/astr.2026.110.3.157
- Author:
Jin Ah LEE
1
;
Dooreh KIM
;
Young Joo LEE
;
Chang Ik YOON
;
Woo-Chan PARK
;
Soo Youn BAE
Author Information
1. Division of Breast Surgery, Department of Surgery, Seoul St Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Publication Type:ORIGINAL ARTICLE
- From:Annals of Surgical Treatment and Research
2026;110(3):157-169
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:Neoadjuvant chemotherapy (NAC) significantly revolutionized the management of locally advanced breast cancer, especially in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative subtypes. However, its effectiveness is limited in estrogen receptor (ER)-positive, HER2-negative breast cancer. This study investigates the clinical response and prognosis of ER-positive, HER2-negative breast cancer after NAC.
Methods:The clinicopathological characteristics and treatment responses of 149 patients with ER-positive, HER2-negative breast cancer treated with NAC and surgery at The Catholic University of Korea, Seoul St. Mary’s Hospital between 2018 and 2023 were retrospectively analyzed. Pathologic complete response (pCR) was defined as the absence of invasive tumors (ypT0/is, ypN0). Disease-free survival (DFS) and overall survival (OS) were analyzed using Kaplan-Meier methods, stratified by age (≤50 years vs. >50 years).
Results:Among 149 patients, 13 (8.7%) achieved pCR, 87 (58.4%) attained partial responses, 40 (26.8%) had stable disease, and 9 (6.0%) experienced progressive disease. RECIST responses differed significantly by age (P = 0.003). DFS (P = 0.011) and OS (P = 0.005) were significantly associated with clinical response in patients aged ≤50 years. Post-NAC Ki-67 was associated with DFS (P = 0.013) but not OS (P = 0.083) in patients aged ≤50 years. Clinical responses and post-NAC Ki-67 were not associated with DFS (P = 0.544) or OS (P = 0.569) in patients aged >50 years.
Conclusion:In ER-positive, HER2-negative breast cancer, clinical responses and post-NAC Ki-67 were significant prognostic factors in patients aged ≤50 years but not in older patients. These findings highlight the need for tailored therapeutic approaches that consider age-specific prognostic differences.
