Current prognostic factors of advanced gastric cancer patients treated with chemotherapy: real world data from a Japanese 12 institutions

Abstract Background Understanding the prognostic factors of advanced gastric cancer before starting chemotherapy is important to determine personalized treatment strategies. However, the details of chemotherapy and the prognosis of advanced gastric cancer patients have changed with the time and environment. The aim of this study was to understand the current reality of chemotherapy and to estimate the prognostic factors of advanced gastric cancer patients before starting chemotherapy at multiple centers. This includes specialized cancer hospitals and community hospitals, with the latest data under the Japanese insurance system. Methods We evaluated the clinical parameters and treatment details of 1025 patients who received systemic chemotherapy for unresectable advanced gastric cancer from 2012 to 2018 at 12 institutions in Japan. Prognostic factors were analyzed using the Cox proportional hazards regression model. Results As of April 2021, 953 (93%) patients had died, while 72 (7%) patients survived. The median overall survival and progression-free survival of first-line chemotherapy was 11.8 months (95% confidence interval, 10.8–12.3 months) and 6.3 months (95% confidence interval, 5.9–6.9 months), respectively. Multivariate analysis revealed eight prognostic factors: age