Prognostic factors in small cell lung cancer: a simple prognostic index is better than conventional staging.

Conventional staging in small cell lung cancer (SCLC) is only of limited prognostic value and is often based on elaborate investigations. We have carried out univariate and multivariate analysis of possible prognostic factors at presentation in 333 consecutive patients with SCLC. Fifteen parameters were found to have individual prognostic significance, of which the most powerful were serum albumin, bone marrow aspirate, disease extent and performance status (all P less than 0.00005). Factors which were not of prognostic significance included age, sex, SVC obstruction, and pleural involvement. Multivariate analysis excluded many factors including bone marrow aspirate as not being independently variable, and a simple combination of clinical performance status, serum albumin and alanine transaminase could be used to define 3 groups (good; medium; poor) of better prognostic significance (survival at 1 year 50% vs. 27% vs. 3%) than conventional limited/extensive disease staging (1 year survival 48% vs. 18%). Other simple combinations of biochemical parameters including plasma sodium and alkaline phosphatase achieved almost as good prognostic groupings. We suggest that consideration should be given to replacing the conventional limited/extensive disease staging system with a simpler system along the lines we have described.