Demographic Disparities in Patterns of Care and Survival Outcomes for Patients with Resected Gastric Adenocarcinoma

Background: Several reports showed incomplete adoption of adjuvant radiotherapy (RT) for resectable gastric cancer since the publication of Intergroup 0116 trial results. The aims of this study were to identify demographic factors associated with omission of adjuvant RT and assess the impact of this omission on survival. Methods: SEER database was queried for cases of resected gastric cancer. Multivariate analyses with logistic and Cox regressions were used to examine (a) likelihood of receiving adjuvant RT for different patient and county demographics and (b) effect of demographics on survival outcomes. Results: A total of 7,348 patients met the study criteria. Adjuvant RT was used in 33.1% of cases diagnosed in 1998-2001 and in 45.3% of cases in 2002-2007 (P < 0.001). Controlling for independent covariates, African Americans were 8.9% less likely to receive adjuvant RT than Caucasians or Asians (P < 0.001). Correspondingly, overall survival rates were significantly lower for African Americans than other races (HR = 1.38, P < 0.001). Furthermore, both the likelihood of receiving RT and the survival rates were significantly affected by county demographics: percent of population without high school education, percent of households below the poverty line, and median household income. Survival rates were highest among Asians, but this finding did not reflect more frequent use of RT. Conclusions: Race and socioeconomic factors are significant predictors of treatment and survival outcomes for patients with resectable gastric cancer. Impact: The findings of this and similar studies may aide the medical community in designing more effective strategies to ameliorate the standards of care nationwide. Cancer Epidemiol Biomarkers Prev; 20(2); 223-33. (C)2011 AACR.