[Statistical studies on multiple primary cancers including gastric cancers].

The incidence of cases with multiple primary cancers was analysed and it was found to have increased chronologically in autopsied cases. The incidence to have another cancer in the patients who underwent operations for gastric cancer was 2.0%, which seemed to be higher than the expect value in the general population. Regarding the cause of death after radical gastric surgery, the multiple primary cancer occupied the second position, the first being the recurrence of gastric malignancy.