Abstract
AIM: To investigate human epidermal growth factor 2 (HER2) overexpression and validate its prognostic effect in stage II-III gastric cancer. METHODS: We reviewed the data of patients who were diagnosed with gastric cancer between March 2008 and October 2013 at the Yonsei University Medical Center. Among these patients, 384 patients who met the inclusion criteria were analyzed retrospectively. RESULTS: Thirty-two (8.3%) of the 384 stage II-III gastric cancer patients exhibited HER2 overexpression. The median follow-up duration was 26.0 mo. HER2-negative patients had superior recurrence-free survival (RFS) compared to HER2-positive patients (HR = 0.52, 95%CI: 0.30-0.89; P = 0.015). The median overall survival (OS) was significantly prolonged in the HER2-negative group compared with the HER2-positive group (55.0 mo vs 38.0 mo, HR = 0.43, 95%CI: 0.21-0.88, P = 0.021). OS was also prolonged in HER2-negative patients who received adjuvant chemotherapy compared to HER2-positive patients (55.0 vs 38.0 mo, HR = 0.42, 95%CI: 0.18-1.00, P = 0.051). In patients who did not receive adjuvant chemotherapy, the median RFS was prolonged in the HER2-negative group compared to the HER2-positive group (not reached vs 12.0 mo, HR = 0.17, 95%CI: 0.06-0.49, P = 0.001). In a multivariate analysis, HER2 status (HR = 0.421, 95%CI: 0.206-0.861, P = 0.018) and Eastern Cooperative Oncology Group performance status (HR = 2.002, 95%CI: 1.530-2.618, P < 0.001) were independent predictors of OS. CONCLUSION: Our findings showed that HER2-positive patients had inferior OS and RFS. Stage II-III HER2-positive patients might be potential candidates for targeted therapies involving trastuzumab.