Neurone specific enolase: a useful diagnostic serum marker for small cell carcinoma of the lung.

Among lung cancers small cell carcinoma is the most sensitive to chemotherapy and radiation. This has emphasised the importance of an accurate diagnosis of this cell type, and the present study examined the use of serum neurone specific enolase (NSE) as a diagnostic marker for small cell carcinoma. NSE was measured in pretreatment sera from 103 patients with small cell carcinoma and in sera from relevant controls, including patients with other lung cancers, non-malignant lung diseases, and healthy adults. Serum NSE concentration was raised (greater than 25 ng/ml) in 72% of patients with small cell carcinoma. Ninety one per cent of patients with extensive disease and 50% of patients with limited disease were serum NSE positive. Patients with extensive disease in general had higher serum NSE concentrations than patients with limited disease. No definite difference in serum NSE positivity could be shown between oat cell and intermediate cell subtypes. Out of 51 patients with other lung cancers, four (8%) had a raised serum concentration, whereas all patients with non-malignant diseases and healthy individuals had normal serum NSE concentrations. Serum NSE determination seems to be a valuable tool for the diagnosis of small cell carcinoma.