Neuron-specific Enolase (NSE)

Neuron specific enolase is one of the five isozymes of the glycolytic enzyme, enolase. This enzyme is released into the CSF when neural tissue is injured. Neoplasms derived from neural or neuroendocrine tissue may release NSE into the blood. The test may have value in predicting response to therapy. In a group of 13 patients with small cell carcinoma of lung, very high levels of NSE (≥100 ng/mL, mean of 490 ng/mL) were found in seven of eight responders. Levels <100 ng/mL (mean 28 ng/mL) were found in the remaining six patients, only two of whom were responders. These values are from samples obtained during the first three-day course of chemotherapy. There is evidence that the level of serum neuron-specific enolase correlates with tumor burden.^1-3 Increase occurs more commonly and is at higher levels in advanced stage than in limited stage disease.³ The enzyme has been elevated in sera of all patients with three or more sites of metastases.¹

Serum NSE levels are increased in cases of neuroblastoma,⁴ but also in other childhood tumors.⁵ Levels >100 ng/mL in children are, however, highly suggestive of advanced neuroblastoma. Use of NSE to monitor treated neuroblastoma patients has not been found to be a sensitive index of residual tumor.⁵ NSE levels may also be increased in some patients with seminoma⁶ and some patients with uremia who have been on dialysis.⁷

1. Johnson DH, Marangos PJ, Forbes JT, et al. Potential utility of serum neuron-specific enolase levels in small cell carcinoma of the lung. Cancer Res. 1984 Nov; 44(11):5409-5414. PubMed 6091878

2. Anastasiades KD, Mullins RE, Conn RB. Neuron-specific enolase: Assessment by ELISA in patients with small cell carcinoma of the lung. Am J Clin Pathol. 1987 Feb; 87(2):245-249. PubMed 3028123

3. Akoun GM, Scarna HM, Milleron BJ, Benichou MP, Herman DP. Serum neuron-specific enolase. A marker for disease extent and response to therapy for small cell lung cancer. Chest. 1985 Jan; 87(1):39-43. PubMed 2981171

4. Ishiguro Y, Kato K, Ito T, Nagaya M, Yamada N, Sugito T. Nervous system-specific enolase in serum as a marker for neuroblastoma. Pediatrics. 1983 Nov; 72(5):696-700. PubMed 6356007

5. Cooper EH, Pritchard J, Bailey CC, Ninane J. Serum neuron-specific enolase in children's cancer. Br J Cancer. 1987Jul; 56(1):65-67. PubMed 3476145

6. Kuzmits R, Schernthaner G, Krisch K. Serum neuron-specific enolase: A marker for response to therapy in seminoma. Cancer. 1987 Sep 1; 60(5):1017-1021. PubMed 2440552

7. DeSanto NG, Veneroso S, Capodicasa G, Crisci A, Giordano C. Tumor markers in uremia: Carcinoembryonic antigen, neuron-specific enolase, carbohydrate antigen CA-50, and alpha-fetoprotein. Am J Nephrol., 1986; 6(6):458-463. PubMed 2436478