Hyung Soon Park1, Joohyuk Sohn1, Seung Il Kim2, Seho Park2, Hyung Seok Park2, Seul Ghi Gho1, Hyun Cheol Chung1, Soonmyung Paik1,3, Gun Min Kim4. 1. Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, 120-752, Seoul, Korea. 2. Department of Surgery, Yonsei University College of Medicine, Seoul, Korea. 3. Department of Biomedical Science, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Korea. 4. Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, 120-752, Seoul, Korea. gmkim77@yuhs.ac.
Abstract
PURPOSE: Trastuzumab-based treatment is the standard care for patients with HER2+ metastatic breast cancer (MBC). About 10% of HER2+ MBC showed a long-term durable response (progression-free survival, PFS > 3 years) to trastuzumab-based therapy. The aim of this study is to identify clinico-pathologic factors for a durable response to trastuzumab-based therapy in HER2-positive MBC. METHODS: In the Yonsei Breast Cancer MBC Database, we identified 1218 MBC patients who were diagnosed from 2006 to 2015. Among them, 294 had HER2+ disease, and 153 received trastuzumab plus taxane chemotherapy as first-line treatment. Clinico-pathologic factors, such as hormone receptor (HR) status and metastatic sites, were reviewed. To evaluate a durable response, landmark analysis was performed. RESULTS: The median follow-up time was 28 months (95% CI 4.4-83.0 months). Of 153 HER2+ patients, there were 73 HR- patients (47.7%), and bone was the most common metastatic site. The median PFS and overall survival (OS) were 12 and 39 months, respectively. HR- patients showed a tendency toward longer PFS (median, 13 vs. 11 months, P = 0.160) compared with HR+ patients. Patients with non-visceral metastases had longer median PFS and OS than those with visceral disease (median PFS, 15 vs. 11 months, P = 0.012; median OS, 75 vs. 34 months, P = 0.03). Landmark analysis at 9 months suggested that the PFS of HR- patients was significantly longer than that of HR+ patients (median, 19 vs. 9 months, P = 0.008). CONCLUSIONS: Among patients with HER2+ MBC, HR status is a possible predictive biomarker of a durable response to trastuzumab-based therapy.
PURPOSE:Trastuzumab-based treatment is the standard care for patients with HER2+ metastatic breast cancer (MBC). About 10% of HER2+ MBC showed a long-term durable response (progression-free survival, PFS > 3 years) to trastuzumab-based therapy. The aim of this study is to identify clinico-pathologic factors for a durable response to trastuzumab-based therapy in HER2-positive MBC. METHODS: In the Yonsei Breast Cancer MBC Database, we identified 1218 MBCpatients who were diagnosed from 2006 to 2015. Among them, 294 had HER2+ disease, and 153 received trastuzumab plus taxane chemotherapy as first-line treatment. Clinico-pathologic factors, such as hormone receptor (HR) status and metastatic sites, were reviewed. To evaluate a durable response, landmark analysis was performed. RESULTS: The median follow-up time was 28 months (95% CI 4.4-83.0 months). Of 153 HER2+ patients, there were 73 HR- patients (47.7%), and bone was the most common metastatic site. The median PFS and overall survival (OS) were 12 and 39 months, respectively. HR- patients showed a tendency toward longer PFS (median, 13 vs. 11 months, P = 0.160) compared with HR+ patients. Patients with non-visceral metastases had longer median PFS and OS than those with visceral disease (median PFS, 15 vs. 11 months, P = 0.012; median OS, 75 vs. 34 months, P = 0.03). Landmark analysis at 9 months suggested that the PFS of HR- patients was significantly longer than that of HR+ patients (median, 19 vs. 9 months, P = 0.008). CONCLUSIONS: Among patients with HER2+ MBC, HR status is a possible predictive biomarker of a durable response to trastuzumab-based therapy.