A clinical study on multiple primary cancer involving the lung and other organs

Fifty-eight patients with multiple primary cancers (5.9%) founding 91 patients with primary lung cancer were studied. The stomach cancer was most frequently associated with lung cancer. All patients with head and neck cancer were heavy smokers, and this fact might suggest that the possibility of the irritating effects of cigarret smoking in the respiratory tract. In patients with double cancer, patients with prior other organ cancer showed the following differences, compared with prior lung cancer. (1) The interval between the first and the second cancer was significantly longer. (2) The clinical stage of lung cancer was more advanced. (3) Lung cancer related death was more frequent. (4) Median survival time was shorter. Earlier diagnosis and treatment of the second cancer may prolong the survival time in patients with multiple primary cancer.