NORMAL SERUM NEURON-SPECIFIC ENOLASE (NSE) VALUE AFTER THE FIRST CYCLE OF CHEMOTHERAPY - AN EARLY PREDICTOR OF COMPLETE RESPONSE AND SURVIVAL IN PATIENTS WITH SMALL-CELL LUNG-CARCINOMA

BACKGROUND. Serum neuron specific enolase (NSE) is the most sensitive tumor marker of small cell lung carcinoma (SCLC) at diagnosis. Its pro gnostic value is still debated. Thus, the authors decided to assess th e predictive value, in terms of complete response and survival, of ser um NSE measured before and after one cycle of chemotherapy in patients with SCLC. METHODS. Sera from 135 patients with histologically proven limited (n = 63) or metastatic (n = 72) SCLC were obtained. Clinical and biologic parameters with a known or suspected prognostic relevance were reviewed. Serum NSE was measured before chemotherapy (D1-NSE) an d 28 days after its initiation (D28-NSE). The prog nostic value of the parameters under study was evaluated in univariate and multivariate a nalyses using the Cox proportional hazards model and logistic regressi on analysis. RESULTS. The level of serum NSE was raised in 120 patient s (88%) prior to therapy. The probability of a normal D28-NSE value wa s not affected by the baseline D1-NSE value. Disease extension (P = 0. 0005), performance status (P = 0.0001), D28-NSE (P = 0.003), and carci noembryonic antigen (CEA) levels (P = 0.008) were found to be predicti ve for survival, whereas age, gender, plasma sodium, serum protides, a nd D1-NSE were not. Median survival and 2-year overall survival were 1 5.3 months and 21% (95% confidence interval [CI], 13-31%) when D28-NSE was normal and 8.1 months and 15% (95% CI, 8-27%) when it was not (P < 0.03). Only performance status (P = 0.001), disease extension (P = 0 .002), and D28-NSE (P = 0.02) were found to be independent prognostic parameters for survival in the multivariate analysis. A simple prognos tic index was developed using these 3 variables. Limited disease, a no rmal D28-NSE value, and a normal CEA value prior to therapy were the o nly parameters predictive for complete response in the univariate anal ysis, and D28-NSE (P = 0.01) and disease extension (P = 0.0001) were f ound to be independent variables in multi variate analysis. A complete response to therapy occurred in 62% with a normal D28-NSE value and i n only 34% in the opposite case, CONCLUSIONS. Normal serum D28-NSE is a strong, independent early predictor of both complete response io the rapy and survival. This simple tool may be proposed for use in the cli nic and in research, in association dth an assessment of disease exten sion and performance status, to predict the outcome of patients with S CLC. (C) 1998 American Cancer Society.