Survival of metastatic gastric cancer: Significance of age, sex and race/ethnicity

Background: Despite the success of modern chemotherapy in the treatment of large bowel cancers, patients with metastatic gastric cancer continue to have a dismal outcome. Identifying predictive and prognostic markers is an important step to improving current treatment approaches and extending survival. Methods: Extracting data from the US NCI's Surveillance, Epidemiology, and End Results (SEER) registries, we compared overall survival for patients with metastatic gastric cancer by gender, age, and ethnicity using Cox proportional hazards models. 13,840 patients (>= 18 years) were identified from 1988-2004. Males and females were categorized by age grouping and ethnicity. Results: 19% of Hispanic patients were diagnosed < 45 years of age as compared to 5.5% of Caucasians. Caucasian patients and men were more likely to be diagnosed with tumors in the gastric cardia (P<0.001). In our survival analysis, we found that women had a lower risk of dying as compared to men (P<0.001). Overall survival diminished with age (P<0.001). The median overall survival was 6 months in patients of <= 44 years old as compared to 3 months in patients 75 years and older. Gender differences in overall survival significantly varied by race and tumor grade/differentiation (P for interaction = 0.003 and 0.005, respectively). Conclusion: This is the largest study of metastatic gastric cancer patients from the SEER registry to show that age, gender, and tumor location are significant independent prognostic factors for overall survival in patients with metastatic gastric cancer.