Trends in gastric cancer incidence: a period and birth cohort analysis in a well-defined French population

Abstract : The incidence of gastric cancer has declined over the past decades. Little is known about trends by site and histological subtype. The aim of this study was to analyze changes in gastric cancer incidence patterns in a French well-defined population. Data on patients with an epithelial gastric cancer diagnosed between 1982 and 2011 were collected by the population-based digestive cancer registry of Burgundy (n = 4694). Time trends in gastric cancer incidence by period of diagnosis and birth cohort were analyzed by sex, subsite, and histological type. There was a decrease in incidence rates for antral carcinomas (-2.6 % per year in males, -2.5 % per year in females; p < 0.001) and corpus carcinomas (-3.3 % and -3.2 %, respectively; p < 0.001). Annual percentage changes were not significant for fundus carcinomas in both sexes and cardia carcinoma in females, although they increased in males (+1.0 % per year; p < 0.02).When comparing the 1900 cohort and the 1950 cohort, there was a five- to sevenfold decrease in the cumulative risk at 0-79 years for corpus and antral carcinomas in both sexes and a threefold decrease for fundus carcinomas. There were minor variations for cardia carcinomas. There was a decrease of incidence both by period of diagnosis and by birth cohort for adenocarcinoma and colloid carcinoma. It was more marked for undifferentiated carcinoma. The variation for signet-ring carcinoma was minor. Temporal variations in incidence rates of gastric cancer differed according to subsite and histology, suggesting different etiological factors. Available analytical studies provide an explanation for the reported trends by subsite.