The monoclonal antibody trastuzumab has brought survival benefit to patients with advanced gastric cancer (AGC) that have human epidermal growth factor receptor 2 (HER2) over expression or amplification. This study was designed to compare the clinical outcomes of HER2-negative and HER2-positive AGC patients with or without trastuzumab treatment. There were three groups of patients enrolled for analysis. Group A was 51 HER2-positive AGC patients treated with trastuzumab and chemotherapy; group B was a matched control group of 47 HER2-positive patients who received chemotherapy only; group C was a matched group of 251 HER2-negative patients who received chemotherapy. All the patients were enrolled at Sun Yat-sen University Cancer Center or Zhongshan Hospital, Fudan University between January 2010 and December 2012. The primary endpoint was overall survival (OS). The Kaplan-Meier method and log-rank test were used for survival analysis. The median duration of follow-up was 13.5 months (range 5–18.6 months). The median OS of these three groups of patients was 14.8 months, 11.3 months and 14.4 months respectively (p< 0.001). The survival difference between group A and B was significant,p< 0.001. Similarly, there was significant difference between group B and C,p< 0.001. Moreover the survival between group A and C was comparable,p= 0.281. The median progression-free survival for these three groups was 7.4, 6.0 and 7.2 months. Multivariate analysis confirmed that trastuzumab treatment was an independent prognostic factor in group A and B patients (p= 0.017). HER2 positive was an independent adverse prognostic factor in group B and C patients (p= 0.013).What's new?
While the association between HER2 status and prognosis in gastric cancer remains controversial, trastuzumab is known to bring survival benefit to advanced gastric cancer (AGC) patients with HER2 overexpression. This is the first study to evaluate the survival difference between HER2-positive, trastuzumab-treated AGC patients and HER2-negative AGC patients in the Chinese population. The data indicated that positive HER2 status was an unfavorable prognostic factor in AGC. In HER2-positive AGC patients, trastuzumab therapy was associated with improved survival compared with trastuzumab-naive controls. The data also supported the notion that HER2-positive, trastuzumab-treated AGC patients can get a similar survival to HER2-negative patients.