Changes in the location and type of gastric adenocarcinoma.

To document our impression of major changes in aspects of gastric adenocarcinoma, we reviewed and compared 62 consecutive cases from 1975 through 1978 and 31 cases from 1938 through 1942. The average age at diagnosis increased from 58 to 68 years, the male to female ratio decreased to approximately 1:1, and carcinomas composed predominantly (50% or more) of signet-ring cells (SRC) increased from 9 to 39% of the total cases. In the recent series, carcinomas with SRC (compared with those without SRC) occurred nine years earlier, were more frequent in women, were located distally, and had an infiltrative growth pattern. Carcinomas originating in the proximal stomach (cardia) were not noted in the old series but formed 27% of the recent cases. These tumors showed a male predominance, contained SRC less often, and were less commonly associated with chronic gastritis. The implications of these observations are discussed.