[Diagnostic usefulness of the determination of serum neuron-specific enolase in small cell bronchial carcinoma].

The plasma level of neuron-specific enolase (NSE) was measured in 55 patients with small cell bronchial carcinoma (SCC) with cytohistological confirmation to evaluate its diagnostic usefulness. As a control group, 132 patients with non-small cell bronchial carcinoma, 81 with non-neoplastic disease and 37 healthy individuals were used. The sensitivity of the test was 84% with a specificity of 79% when values below 13 ng/mg were considered as normal. To achieve a specificity of 95% and 99% cutoff values had to be increased to 25 and 50 ng/ml, respectively, and then the sensitivity was reduced to 51% and 38%. There were false positive findings in the three control groups, although they were more common (28%) and had higher values in patients with widespread disease the sensitivity was significantly higher (p less than 0.005) than in those with limited disease. Carcinoembryonic antigen, which was measured with comparative purposes, had a lower sensitivity. In our area, a NSE level over 50 ng/ml is closely correlated with the diagnosis of SCC, whereas values over 13 ng/ml select a wider group of individuals where most patients with this type of carcinoma are included.