Stomach cancer: major trends in incidence during introduction of gastroscopy service in Norway.

The age-adjusted incidence of stomach cancer has been studied during the introduction of gastroscopy service in Norway. The incidence showed an annual decrease of 3.5% for both sexes. More cases were classified within anatomic subsites. For men there was a decreasing incidence for cancers located in the antrum, for extensive tumours and for not otherwise specified (NOS) disease. No significant changes were found for cancer of the body or the cardia/fundus. In women a decrease in incidence was noted for the NOS subgroup, an increase was seen for tumours of the gastric body, and no significant changes were found for antral cancers or for tumours of the cardia/fundus. A marked increase in incidence was noted for gastric stump cancers for both sexes. During this period a shift in staging towards less advanced disease occurred. In conclusion, the increased diagnostic accuracy and the shift in staging of the disease may suggest that the introduction of gastroscopy service has been effective.