THE CLINICAL-VALUE OF NEURON-SPECIFIC ENOLASE AS A TUMOR MARKER IN BRONCHOALVEOLAR LAVAGE

Background. Neuron-specific enolase (NSE) is used in the staging and monitoring of responses to therapy and the detection of recurrences in lung cancer. The diagnostic value of NSE has been under discussion. This may be because NSE usually has been studied in the sera of patients with bronchogenic carcinoma and not in the bronchoalveolar lavage (BAL). Methods. The NSE levels in the BAL of three groups-control subjects, patients with chronic bronchitis, and patients with tumors-were analyzed. The fluid obtained was centrifuged. The NSE was analyzed in the supernatant of the BAL (NSE, Pharmacia, Columbia, MD). Its concentrations were calculated in relation to milligrams of total protein. Results. A significant difference was noted in the level of NSE in the BAL of the tumor group compared with those of the other two groups. No differences were observed between the other two groups or between healthy smokers and nonsmokers. No correlation was found with the histologic type of pulmonary carcinoma and NSE levels in BAL. The NSE levels were higher in the lavages of patients with primary pulmonary carcinomas than in those with metastases. Conclusions. Neuron-specific enolase could be of aid in the early diagnosis of solitary pulmonary nodules and lung cancer. More studies would be required to identify a correlation between NSE levels in BAL and those in serum, or between NSE levels in BA, and tumor size and location and disease stage of lung cancer.