Descriptive epidemiology of adenocarcinomas of the cardia and distal stomach in the Swiss Canton of Vaud.

Incidence registration and survival data from various anatomical subsites of gastric cancer have been abstracted from the population-based Cancer Registry of the Swiss Canton of Vaud for the period 1976-87. Overall age-standardized (Vaud population in 1980) incidence rates for all gastric adenocarcinomas were 22.2/100,000 males and 8.3/100,000 females, with a sex ratio of 2.7. The male preponderance was appreciably greater for cardia (5.9 vs 0.9, sex ratio = 6.5) than for distal stomach (10.2 vs 5.0, sex ratio = 2.0). Adenocarcinomas of unspecified origin had an intermediate sex ratio (2.6). The sex ratio for all gastric adenocarcinomas was lower in the third and fourth decades of age (1.3) than at older ages. In relation to calendar period of diagnosis, no appreciable trend with time was observed for adenocarcinomas of the cardia, and only some modest decline was observed for distal stomach, in the presence of stable sex ratios. A marked fall was observed for "other and unspecified" subsites. Thus, the overall decline in the incidence of gastric adenocarcinomas over the calendar period considered was about 20% for males and 30% for females. Five-year survival was significantly higher for cancers arising in the distal stomach (30%) than for cardiac carcinomas (11%), and intermediate for "other and unspecified sites" (19%). These results indicate that adenocarcinomas arising from the cardia and those arising from the distal stomach are considerably heterogeneous in relation to descriptive epidemiology and prognosis. This may have relevant etiological correlates, particularly since carcinoma of the cardia appears to share important epidemiologic features with esophageal cancer.