Long-term survival of surgical cases of lung cancer

The survival rate and important prognostic factors were studied in patients observed for more than 10 years after surgery for squamous cell carcinoma and adenocarcinoma. The causes of death of long-term survivors and whether 5- or 10-year survival assures complete cure were also examined. The records of 324 patients operated on at Kyoto University Chest Disease Research Institute between January 1976 and May 1984 were analyzed. Five- and 10-year survival of these patients was 34.4 and 26.8%, respectively. There was no difference between the survival rate of adenocarcinoma and squamous cell carcinoma. Significant difference were noted in survival curves between stage I, II and IIIa, and stage IIIa and IIIb cancers (P = 0.001, P = 0.005, and P = 0.001, respectively). A significant difference in the survival curve was also observed between those with complete and with incomplete resection (P < 0.0001). Multivariate analysis using Cox proportional hazards method showed that ages, pathological N-factor, and complete resection were significant prognostic factors. Nine of the 16 patients who died between 5 and 10 years after surgery had recurrent or second primary lung cancer. Five of these nine patients were diagnosed as recurrence or distant metastases. Of the 39 patients who survived disease-free for 10 or more years after surgery, none died of new recurrence. It is speculated that 5-year survival would not indicate complete cure after surgery for lung cancer and patients should be followed up for more than 10 years.