Neuroendocrine differentiation in renal cell carcinoma--evaluation of chromogranin A and neuron-specific enolase.

Chromogranin A and neuron-specific enolase (NSE) as neuroendocrine markers were evaluated in 200 patients with renal cell carcinoma, and 15 patients with benign renal cysts. Immunoassays of serum levels and immunohistochemical staining of tumour tissue were performed. Serum chromogranin A was elevated in 28 (14%) patients with renal cell carcinoma, but the levels did not differ from those for patients with benign cysts. Serum NSE was elevated in 54 (27%) patients, significantly higher compared with controls (p = 0.0002). Serum chromogranin A level was positively correlated to serum creatinine and age, but not to tumour stage or grade. Serum NSE level was positively correlated to tumour stage and grade, but not to serum creatinine or age. Immunohistochemical staining for chromogranin A was positive in 1 of 24 (4%), and for NSE in all 18 (100%) tumours analysed. In a multivariate analysis, tumour stage, grade, and serum NSE, but not chromogranin A, were significant predictors of prognosis.