Neuron-specific enolase during chemotherapy of small cell lung cancer

Serum neuron-specific enolase (NSE) has been measured in 28 patients with small cell lung cancer (SCLC) and 90 patients with other forms of lung cancer (NSCLC), i.e., 28 with adenocarcinoma and 62 with squamous cell carcinoma. Increased NSE (greater than 12.0 micrograms/liter) was found in 71.4% of SCLC patients and in 22.2% of NSCLC patients. The predictive value of an increased NSE in identifying SCLC was only 50%, whereas the predictive value of a normal NSE in differentiating SCLC for NSCLC was 91%. Serial studies during chemotherapy of SCLC patients showed that the doubling time of NSE ranged from 7 to 127 days and the mean apparent half-life (AHL) of NSE to be 14 days. AHL values in excess of 20 days suggest that the tumour is not in full remission. We believe that measurement of serum NSE and calculation of the AHL and DT are valuable in identifying the effectiveness of chemotherapy in patients with SCLC.