Liver Metastases in Newly Diagnosed Gastric Cancer: A Population-Based Study from SEER

Purpose: Population-based data on the proportion and prognosis of liver metastases at diagnosis of gastric cancer are currently lacking. Besides, the treatment of gastric cancer with liver metastases is still controversial now. Methods: Patients with gastric cancer and liver metastases (GCLM) at the time of diagnosis in advanced gastric cancer were identified using the Surveillance, Epidemiology, and End Result (SEER) database of the National Cancer Institute. Multivariable logistic and Cox regression were performed to identify predictors of the presence of GCLM at diagnosis and factors associated with all-cause mortality. Results: We identified 3507 patients with gastric cancer and liver metastases at the time of diagnosis, representing 16.89% of the entire cohort and 44.12% of the subset with metastatic disease to any distant site. Among entire cohort, multivariable logistic regression identified thirteen factors (age, race, sex, original, tumor location, pathology grade, Lauren classification, T staging, N staging, tumor size, number of extrahepatic metastatic sites to bone, lung, and brain, insurance situation and smoking) as predictors of the presence of liver metastases at diagnosis. Median survival among the entire cohort with GCLM was 4.0 months (interquartile range: 1.0-10.0 mo). Patients receiving comprehensive therapy had longer median overall survival, of which the median survival was 12.0 months (interquartile range: 6.0-31.0 mo). Multivariable Cox model in SEER cohort confirmed nine factors (age, tumor location, Lauren classification, T staging, number of extrahepatic metastatic sites to bone, lung, and brain, surgery, chemotherapy, RSC and marital status) as independent predictors for overall survival. Conclusions: The findings of this study provided population-based estimates of the proportion and prognosis for LM at time of GC diagnosis. These findings provide preventive guidelines for screening and treatment of LM in GC patients.