NEURON-SPECIFIC ENOLASE AS A MARKER OF BRAIN METASTASIS IN PATIENTS WITH SMALL-CELL LUNG-CARCINOMA

Neuron-specific enolase (NSE) is one of the iso-forms of enolase, a gl ycolytic enzyme found in the neuroendocrine system. NSE is one of the most widely used tumor markers in small-cell lung carcinoma (SCLC). To assess the value of NSE in discriminating between the sites of metast ases in SCLC-patients with and without cerebral involvement, serial NS E determinations were performed. Serum NSE was elevated in 76% of the patients at initial diagnosis. The value did not discriminate between the extent of disease nor between the sites of extrathoracic disease. NSE levels declined significantly at restaging. A persistent, signific ant rise occurred in patients with relapse of their disease, regardles s of the site of relapse. In patients with brain metastases with and w ithout extracranial disease at relapse, the NSE increase was significa ntly smaller than in patients without intracranial involvement. These findings indicate that serial determination of serum NSE in SCLC-patie nts may be useful in monitoring tumor activity but not in predicting t he site of metastatic disease.