Trend in incidence of adenocarcinoma of the esophagus in Japan, 1993-2001

Background: Several studies with population-based cancer registry data have suggested that incidence of adenocarcinoma of the esophagus has been increasing since 1970 in some European and North American countries and Australia. However, data from Asian countries with regard to the incidence of esophageal cancer by histological type based on the population-based cancer registry are lacking. The aim of this study was to describe the incidence of esophageal cancer by histological type in a Japanese population. Methods: Cancer incidence data for 1993-2001 from 15 population-based cancer registries were collected by the Japan Cancer Surveillance Research Group in 2005. We used data from eight registries corresponding to inclusion criteria for data quality. Results: Squamous cell carcinoma remains the predominant type in all esophageal cancers in Japan. The ratio of squamous cell carcinoma to adenocarcinoma is 26:1. For adenocarcinoma, estimated average annual percentage change was 4.7% (95% confidence interval: 0.7, 8.9) in men and 6.0% (2.4, 9.8) in women. Age-adjusted incidence rate (the world standard population) per 100 000 for 2001 was 0.3 in men and 0.05 in women. Incidence of squamous cell carcinoma was increasing slightly in men and nearly constant in women. Age-adjusted incidence rate for 2001 was 8.2 in men and 1.0 in women. Conclusion: No dramatic increase in adenocarcinoma has occurred, and absolute incidence remains low in Japan.