Survival following resection for lung cancer as a second primary cancer.

A second operation was done on 59 patients with lung cancer (7.4% of all those with lung cancer) as a second primary (double primary), during 1974-1991. There were 16 synchronous tumors (interval less than one year) and 43 metachronous tumors (interval over one year). The criteria for diagnosing lung cancer as a second primary from intrapulmonary metastases were any of the following: 1) different histologic type; 2) origin from carcinoma in situ; 3) gross appearance suggestive of primary lung cancer. The initial operation was in the stomach in 14 patients and in the lung in 10. The overall 5-year survival rate in the double primaries was 57.8%, and the prognosis was similar to those in the single primaries of the lung. Nineteen patients died from the second tumor following the second operation, compared with 5 from the initial tumor. The incidence of primary lung cancer increases, and close follow-up after resection for malignant neoplasms detects a new shadow in the chest roentgenogram. It offers a chance of early detection of primary lung cancer and subsequent resection with acceptable results.