A Retrospective Analysis for Patients with HER2-Positive Gastric Cancer Who Were Treated with Trastuzumab-Based Chemotherapy: In the Perspectives of Ethnicity and Histology

• Published in: Cancer research and treatment Vol. 48; no. 2; pp. 553 - 560
• Main Authors: Yi, Jun Ho, Kang, Jung Hun, Hwang, In Gyu, Ahn, Hee Kyung, Baek, Hyun Jin, Lee, Soon Il, Lim, Do Hyoung, Won, Young-Woong, Ji, Jun Ho, Kim, Hyo Song, Rha, Sun Young, Oh, Sung Yong, Lee, Kyung Eun, Lim, Taekyu, Maeng, Chi Hoon, Kim, Moon Jin, Kim, Seung Tae, Lee, Jeeyun, Park, Joon Oh, Park, Young Suk, Lim, Ho Yeong, Kang, Won Ki, Park, Se Hoon
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Cancer Association 01.04.2016; 대한암학회
• Subjects: Adult; Aged; Aged, 80 and over; Antineoplastic Agents, Immunological - therapeutic use; Asian Continental Ancestry Group; Female; Histology; Humans; Male; Middle Aged; Original; Receptor, ErbB-2 - metabolism; Retrospective Studies; Stomach Neoplasms - drug therapy; Stomach Neoplasms - ethnology; Stomach Neoplasms - metabolism; Stomach Neoplasms - pathology; Trastuzumab - therapeutic use; 의약학; Histology; Stomach neoplasms; Trastuzumab; Ethnic groups; ErbB-2 receptor
• ISSN: 1598-2998; 2005-9256; 2005-9256
• DOI: 10.4143/crt.2015.155

While the Trastuzumab for Gastric Cancer (ToGA) trial demonstrated the efficacy and safety of trastuzumab-based chemotherapy in HER2-positive metastatic gastric cancer, the overall survival (OS) benefit was not found in Asian and diffuse-type cancer patients. The aim of the study is to investigate predictive markers for trastuzumab-based chemotherapy. Data of patients with HER2-positive gastric cancer treated with trastuzumab-based chemotherapy were analyzed retrospectively. A total of 168 Asian patients were included. The median age was 60 years (range, 27 to 85 years) and the male:female ratio was 118 (70.2%):50 (29.8%). Fourteen (8.3%), 63 (37.5%), 75 (44.6%), and 11 (6.5%) patients had well, moderately, poorly-differentiated tubular adenocarcinoma and signet ring cell carcinoma, respectively. With 14 complete responses and 73 partial responses, the response rate was 50.6%. The median progression-free survival (PFS) was 10.2 months (95% confidence interval [CI], 8.7 to 11.7), and the median OS was 18.5 months (95% CI, 16.4 to 50.6). Next, we investigated the effect of poorly-differentiated histology (PDH, poorly-differentiated tubular adenocarcinoma+signet ring cell carcinoma) on clinical outcomes. The median PFS (8.9 months vs. 11.5 months, p=0.16) was slightly inferior in PDH patients, and the median OS was significantly shorter in PDH patients (14.6 months vs. 19.0 months, p=0.025). While subset analysis of the ToGA trial demonstrated that trastuzumab-based chemotherapy may not be beneficial for Asians and patients with PDH, our data may suggest that even in Asian patients and patients with PDH, trastuzumab-based chemotherapy could be associated with improved clinical outcomes in patients with HER2-positive gastric cancer.