Significant Racial Disparities Exist in Noncardia Gastric Cancer Outcomes Among Kaiser Permanente's Patient Population.

ABSTRACT

INTRODUCTION: Racial and ethnic differences in gastric cancer are not well understood. This study sought to compare the clinicopathological features and survival of noncardia gastric adenocarcinoma (NCGA) patients with different racial/ethnic backgrounds in Kaiser Permanente Northern California (KPNC), a large integrated health care system. METHODS: This was a retrospective cohort study of 1,366 patients with newly diagnosed NCGA between 2000 and 2010. The subjects were categorized into four racial/ethnic groups non-Hispanic Whites, Blacks, Asians, and Hispanics. Clinicopathological information and survival data were obtained from the KPNC electronic databases and compared among the four racial/ethnic groups. RESULTS: The incidence of NCGA declined in Blacks and Whites, but remained stable in Asians and Hispanics. Whites had a lower incidence of NCGA compared with non-Whites. Asians and Hispanics were diagnosed at a younger age compared with Whites (mean age at diagnosis 66, 63, and 72 years, respectively; P < 0.0001). Diffuse/mixed histological type (Lauren classification) was more prevalent in Asians and Hispanics than in Whites and Blacks (46 and 45 vs. 36 and 29 %, respectively, P = 0.001). History of Helicobacter pylori testing was associated with better survival. Asians had the highest survival rates at 1, 2, and 5 years, while Whites had the lowest (P < 0.0001). CONCLUSIONS: Significant racial/ethnic differences exist in patients with noncardia gastric cancer. Asians and Hispanics were younger at diagnosis and had more diffuse/mixed histological type. Asians had the highest survival, while Whites had the lowest. Such differences may be related to biological, environmental, and treatment-related factors.