Prognostic factors in advanced non-small cell lung cancer: Elevated serum levels of neuron specific enolase indicate poor prognosis

Background: Non-small cell lung cancer (NSCLC) is resistant to chemotherapy and prognosis of advanced NSCLC patients is considered to be dependent on various prognostic factors. Methods: We analyzed prognostic factors in patients with advanced NSCLC who had been enrolled in clinical trials conducted by the Okayama Lung Cancer Study Group between 1978 and 1992 using two kinds of multivariate analysis, Cox's multivariate analysis and recursive partitioning and amalgamation (RPA) analysis. Results: The first analysis was performed on 261 patients using 28 variables. Performance status (PS), clinical stage, liver metastasis or serum albumin level was an independent prognostic factor by Cox's analysis. In the second analysis performed on 128 patients having data on neuron specific enolase (NSE), NSE was the most important prognostic factor. Using the RPA method, three subgroups with significantly different survival potentials were defined. Among them, patients with normal serum NSE levels and good PS were found to obtain a markedly favorable prognosis [median survival time (MST) 22.1 months, 3-year survival rate 42.9%], whereas the survival of patients with elevated serum NSE levels and bone metastasis was extremely short (MST 4.7 months, 3-year survival rate 0%). Conclusions: These results indicate that analysis of prognostic factors including serum levels of NSE is useful for predicting the survival of patients with advanced NSCLC.