Incidence of esophageal and gastric carcinomas among American Asians/Pacific Islanders, whites, and blacks: Subsite and histology differences

BACKGROUND. The authors examined subsite-specific and histology-specific esophageal and gastric carcinoma incidence patterns among the Asians/Pacific Islander (API) population in the United States and compared them with those among whites and blacks. METHODS. Data on newly diagnosed esophageal and gastric carcinomas during 1996-2000 were obtained from 24 population-based central cancer registries, representing approximately 80% of the API population in the United States. Age-adjusted rates, using the 2000 United States standard population, and age-specific rates were computed by anatomic subsite, histology, race, and gender. The difference in the age-adjusted rates between APIs and other races were examined using the two-tailed z statistic. RESULTS. Greater than 75% of esophageal carcinomas among APIs, both males and females, were squamous cell carcinoma. Adenocarcinoma accounted for < 20% of all esophageal carcinomas. This pattern was similar to that among blacks but was completely opposite to that among whites. The rate of esophageal squamous cell carcinoma was 81% higher among API males compared with white males, but it was 64% less compared with black males. The rates of esophageal adenocarcinoma were significantly lower among APIs than among both whites and blacks both males and females. The majority of gastric carcinomas among APIs were noncardia adenocarcinoma, whereas cardia adenocarcinoma accounted for only 11% of gastric carcinomas among API males and 6% of gastric carcinomas among API females. The age-adjusted incidence rate of cardia adenocarcinoma was 23% lower among API males compared with white males, but it was 26% higher compared with black males. In contrast, the rates of noncardia adenocarcinoma among APIs were approximately 3.7 times the rate among whites for both males and females and 33% higher than the rate among blacks. CONCLUSIONS. Subsite-specific and histology-specific incidence patterns of esophagogastric carcinoma among APIs differ from those among whites and blacks. The reasons for significantly higher rates of noncardia adenocarcinoma among APIs compared with whites and blacks need further investigation.