Neuron-specific enolase (NSE) as a tumour marker and comparative evaluation with carcinoembryonic antigen (CEA) in small-cell lung cancer.

Serum neuron-specific enolase (NSE) was evaluated in a number of malignant tumours. It was elevated (greater than 12.5 micrograms l-1) in 13/17 (76.5%) patients with extensive small-cell lung carcinoma and in none of the three patients with limited disease. Of patients with carcinoma of the breast 4/12 (33.3%) had elevated concentrations. Normal concentrations were found in patients with non-Hodgkin's lymphoma (19) and Hodgkin's disease (15), carcinoma of the cervix (2), CSF and serum (5) of patients with gestational trophoblastic disease (with definite nervous system involvement). Comparative serial studies of NSE and carcinoembryonic antigen (CEA) concentrations were done in 15 patients with small-cell lung cancer (SCLC). Of these 7/15 (46.7%) had elevated pre-treatment concentrations of both CEA and NSE, 1/15 (6.7%) had CEA elevated only, while 2/15 (13.3%) had NSE alone elevated. Of those patients with normal pre-treatment marker concentrations 3/5 (60%) had elevated markers on recurrence. The mean survival period was 61.9 weeks; 66.8 weeks for the marker-negative group and 44.6 weeks for the marker-positive (both NSE and CEA) group. Combined NSE and CEA evaluation provide additional means of monitoring SCLC.