Asian Americans have better outcomes of non-metastatic gastric cancer compared to other United States racial groups: A secondary analysis from a randomized study

BACKGROUND: It has been recognized for a long time that gastric cancer behavior and outcomes might be different between patients living in Asian countries vs patients living in Western countries. It is not clear if these differences would persist between patients of Asian ancestry and patients of other racial subgroups within the multiethnic communities of North America. The current study hypothesizes that these differences will present within North American multiethnic communities. AIM: To evaluate the impact of race on survival outcomes of non-metastatic gastric cancer patients in the United States. METHODS: This is a secondary analysis of a randomized controlled trial (CALGB 80101 study) that evaluated two adjuvant chemoradiotherapy schedules following resection of non-metastatic gastric cancer. Kaplan-Meier analysis and log-rank testing were utilized to explore the overall and disease-free survival differences according to the race of the patients. Univariate and multivariate Cox regression analyses were then used to explore factors affecting overall and disease-free survivals. RESULTS: A total of 546 patients were included in the current analysis. Of which, 73.8% have white race (vs 12.8% black Americans and 8.2% Asian Americans). Using Kaplan-Meier analysis/log-rank testing, Asian Americans appear to have better overall and disease-free survival outcomes compared to other United States racial groups (White Americans, Black Americans, and other racial groups) (P = 0.011; P = 0.010; respectively). Moreover, in an adjusted multivariate model, Asian American race seems to be associated with better overall and disease-free survival (hazard ratio: 0.438; 95% confidence interval: 0.254-0.754), P = 0.003; hazard ratio: 0.460; 95% confidence interval: 0.280-0.755, P = 0.002; respectively). CONCLUSION: Asian American patients with non-metastatic gastric cancer have better overall and disease-free survival compared to other racial groups in the United States. Further preclinical and clinical research is needed to clarify the reasons behind this observation.