[Nineteen multiple primary cancer cases of 100 patients undergoing lung cancer resection].

In our department, half of 100 consecutive lung cancer resection cases were over the age of 70 years. In the same 100 patients, nineteen cases had multiple primary cancers. Sixteen cases had double, two cases had triple, one case had quadruple primary cancers. The incidence rate of multiple primary cancers involving the lung was 19%. This incidence of 19% is higher than the others ever reported in Japan. It was concluded, when lung cancer patients were elder, that there was increasment in the frequency of multiple cancer cases involving lung, and there was a high possibility of the occurrence of 2nd and 3rd primary cancers.