SERUM NEURON-SPECIFIC ENOLASE: A MARKER FOR DISEASE EXTENT AND RESPONSE TO THERAPY OF SMALL-CELL LUNG CANCER

Serum neuron-specific enolase (NSE) levels in 94 newly diagnosed untreated patients with small-cell lung cancer (SCLC) were compared with those in 30 adult controls. 38 of the SCLC patients had limited disease and 56 had extensive disease. Serum NSE was raised (>12·0 ng/ml) in 69% of all patients (mean 52·35±11·56, range 4·1-850 ng/ml); it was raised in 15/38 (39%) of patients with limited stage disease and in 49/56 (87%) of those with extensive stage disease. Extensive stage patients had a significantly higher mean NSE level (59 ng/ml) than did limited stage patients (13·8 ng/ml). Serum NSE was raised in 34/41(84%) of patients with metastases at 1 or 2 sites and in all 15 patients with metastases at 3 or more sites. Serial measurements in 23 patients receiving combination chemotherapy showed an excellent correlation between serum NSE and clinical response. Continuous cell-lines of SCLC, established from 10 of the patients in this study, all expressed high levels of NSE. These studies indicate that serum NSE may be a useful marker for staging and for monitoring response to therapy in patients with SCLC.