A decline in carcinoma of the stomach. A diagnostic artifact?

During the past 50 years or more, a dramatic decline in the mortality from gastric carcinoma has been observed in virtually every country in the world, including the United States. Some investigators suspect that this decline is due to refinements in the diagnosis and classification of abdominal malignancies rather than being a true decline in the incidence of gastric cancer. Because the record system in Rochester, Minnesota, ensures the identification of virtually every patient in the local population with a serious illness, and the level of diagnosis is high, it seemed appropriate to study the incidence and long-term trends of gastric cancer in this community. Trend analysis for the period 1935 through 1979 revealed a consistent decline in the incidence of gastric carcinoma whether death certificates as the sole source of cases were included or not. Analysis of either all clinically confirmed or only tissue-confirmed cases revealed a statistically significant decrease in stomach carcinoma throughout the study period. These declines were observed even if only the more recent periods (1955 through 1979) were examined. The reasons for this finding remain obscure, but the study suggests that improvements in diagnostic accuracy alone cannot account for this remarkable downward trend in gastric malignancy.