Chronological improvement of survival in patients with advanced gastric cancer over 15 years

Background: Recent trials have reported a median overall survival (OS) of 11–17 months in patients with advanced gastric cancer (AGC). However, it is unclear how recently approved drugs contribute to patient prognosis. Objectives: We aimed to evaluate the characteristics and survival in patients with AGC over the past 15 years. Design: Retrospective study. Methods: We evaluated data of 1355 patients with AGC who received first-line chemotherapy between January 2005 and March 2019 at a single institution. We compared the characteristics and survival rates across four periods: January 2005–December 2007 (period A), January 2008–February 2011 (period B), March 2011–May 2015 (period C), and June 2015–March 2019 (period D). The median follow-up duration was 13.1 months, with 312, 333, 393, and 317 patients in periods A, B, C, and D, respectively. Results: There were no significant differences in patient characteristics between the four periods, except for the proportion of patients who underwent prior gastrectomy and human epidermal growth factor receptor 2 (HER2) testing. Patients in period D had significantly longer OS than those in period A [median: 15.7 versus 12.4 months; adjusted hazard ratio (aHR): 0.79; p = 0.02]. The mean OS in patients with liver metastasis (LM) in period D was remarkably longer than that in patients in period A (median: 19.3 versus 12.4 months; aHR: 0.61; p < 0.01), while that in patients with peritoneal metastasis showed limited improvement. Conclusion: Clinical strategy changes, including gastrectomy, HER2 testing, and approval of new drugs, may be associated with improved OS in patients with AGC. In the last 4 years, a remarkable improvement has been observed in patients with LM.