Marked multi-ethnic variation of esophageal and gastric cardia carcinomas within the United States.

OBJECTIVE: No prior studies have contrasted esophageal and gastric cardia carcinoma incidence rates among multiple ethnicities. We evaluated whether these adjacent cancers differ; such detailed demographic analyses would inform risk factor, screening, and intervention studies.
METHODS: We contrasted incidence rates and temporal trends from the Surveillance, Epidemiology, and End Results (SEER) cancer registry data between 1992 and 1998 for five groups: non-Hispanic whites (Caucasians), white Hispanics (Hispanics), blacks, Asians/Pacific Islanders (Asians/PI), and Native Americans (NA).
RESULTS: Caucasian males' esophageal adenocarcinoma rate (4.2 per 100,000 population/yr) was double that of Hispanics and four-fold higher than those of blacks, Asians/PI, and NA (p < 0.01). Female rates were much lower than male rates for all ethnicities. Similar to esophageal adenocarcinoma, cardia adenocarcinoma rates were highest in Caucasian males (3.4 per 100,000 population/yr); however, the ethnic differences were much less and female rates were comparable for all almost all ethnicities (range 0.6-0.7 per 100,000 population/yr) except NA. Esophageal adenocarcinoma incidence rates increased significantly only in Caucasians (males 5.6%/yr, females 9%/yr; p < 0.05) and cardia cancer rates did not increase for any ethnicity during this period. In contrast, esophageal squamous cell carcinoma incidence rates were highest in blacks (8.8 per 100,000 population/yr) and Asians/PI (3.9 per 100,000 population/yr) and rates were stable or declined for all ethnicities between 1992 and 1998.
CONCLUSIONS: Esophageal and cardia carcinoma incidence rates vary much more markedly by ethnicity and gender than previously reported and the two sites differ from each other. Current putative risk factors do not adequately explain these large differences. These data have implications for risk factor, screening, and intervention studies.