Abstract
A clinical study was made on synchronous double primary cancer in patients with lung cancer who were operated on in the hospital from July 1987 to Decenber 1996. Of a series of 544 patients with primary lung cancer, 18 (3.3%) patients had double cancer. There were 15 men and three women. The organs where the another primary cancer arose in were the lung in five cases, the stomach in five cases, the large intenstine in two cases and the esophagus, kidney, liver, prostate, thyroid, and uterus in each one case. The lung cancer was the first neoplasm in eight cases and the second in 10 cases. The second cancer was commonly detected by preoperative x-ray examination or by CT during clinical observation on outpatient basis after the operation for the first cancer. The cumulative 5-year survival rates were 30.0% in 18 cases of double cancer and 37.7% in all op-erated cases of lung cancer. Therer was no great difference.
