Prospective population-based study on the survival of patients with lung cancer.

The purpose of this study was to evaluate the change, over 20 yrs, in the survival of lung cancer patients in a population-based study. Information on all patients with lung cancer in a defined geographical area during 1990-1992 (n=602) was prospectively gathered. The survival of these patients was assessed and also compared with the results of a similar study in the same area during the years 1968-1971 (n=446). The 5-yr survival had improved during 20 yrs from 4% to 12%. The 5-yr survival of the patients with squamous cell carcinoma had increased from 6% to 16%, and adenocarcinoma from 4% to 19%, whereas the survival of small cell carcinoma had remained the same (2% and 3%, respectively). Even though the recent patients were older than those of the earlier series the proportion of surgically treated patients had remained the same (16% and 20%), but the 5-yr survival of patients who had been operated on had increased significantly from 23% to 48%. The differences in survival in the second cohort (1990-1992) between histological types (Chi-squared logrank=59.2), tumour, node, metastasis stages (Chi-squared logrank=199.6), symptomatic stages (Chi-squared logrank=120, p<0.001) and treatment (Chi-squared logrank=277) were significant. Based on this study the independent prognostic factors for better survival of lung cancer patients are tumour, node, metastasis stages I and II, surgical treatment and Feinstein's symptomatic stages I and II.