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

introductionRacial 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.

methodsThis 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.

resultsThe 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).

conclusionsSignificant 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.