Gastrectomia e strategie multimodali nel trattamento del cancro gastrico in stadio IV: risultati oncologici di 16596 pazienti

Objectives This population-based study aimed to investigate the survival benefit of treatment strategies in metastatic gastric cancer (GC) patients, focusing on role and timing of gastrectomy. Methods We included eligible stage IV GC patients in the Surveillance, Epidemiology and End Results (SEER) database from 2004 to 2015. Overall (OS) and Cancer Specific Survival (CSS) rates were calculated by Kaplan–Meier analysis and log-rank test. Multivariate Cox analysis was performed to analyze the effect of gastrectomy performed alone, before (Primary gastrectomy, PG) or after (Secondary Gastrectomy, SG) chemotherapy. Finally, we performed a propensity score matching (PSM) to reduce the potential selection bias. Results A total of 16596 patients were extracted, including 6819 (41.1%) underwent chemotherapy, 1244 (7.5%) gastrectomy, 1031 (6.2%) PG and 220 (1.3%) SG. The median OS time was significantly higher (P<0.001) in SG patients (15 months) than in PG (13 months), G (6 months) and chemotherapy (6 months) group, respectively. In the multivariate Cox analysis, SG was associated with better OS (HR=0.27; 95%CI=0.22-0.34; P<0.001) and CSS (0.28, 95%CI=0.23-0.35, P<0.001) compared to PG (OS: HR=0.31; 95%CI=0.27-0.36; P<0.001; CSS: HR= 0.31, 95%CI=0.27-0.36, P<0.001), gastrectomy (OS: HR=0.50; 95%CI=0.43-0.57, P<0.001; CSS: HR 0.49, 95%CI=0.43-0.57, P<0.001) and chemotherapy (OS: HR=0.41; 95%CI=0.39-0.44, P<0.001; CSS: HR= 0.41, 95%CI=0.39-0.44, P<0.001), respectively. The survival benefits of SG persisted even after the PSM analysis (OS: HR=0.74, 95%CI=0.59-0.93, P=0.009; CSS: HR=0.75, IC95%0.59-0.94, p=0.012). Conclusions Based on population-based study, we demonstrated that there was a survival advantage of gastrectomy in stage IV GC patients, especially after chemotherapy. Our findings needs to be investigate in further prospective studies.