Circulating neuroendocrine markers in patients with prostate carcinoma

Abstract

Background: Circulating neuroendocrine markers were measured in patients with prostate carcinoma (PC), prostatic intraepithelial neoplasia (PIN), and benign prostatic hypertrophy (BPH) with the goal to: 1) evaluate the differences in the expression of these markers in patients with benign, premalignant, and primary or metastatic PC; 2) evaluate their prognostic significance; 3) compare values in patients with hormone-naive and hormone-refractory disease; and 4) assess changes after androgen deprivation or chemotherapy.

Methods: Serum neuron specific enolase (NSE) (immunoradiometric assay) and plasma chromogranin A (CgA) (enzyme-linked immunoadsorbent assay) were evaluated in 141 patients with BPH, 54 patients with PIN, and 159 patients with PC; 119 patients were bearing hormone-naive disease and 40 were bearing hormone-refractory disease. CgA was monitored in 31 patients submitted to androgen deprivation and in 24 patients receiving chemotherapy.

Results: Supranormal CgA was observed more frequently in patients with American Urologic Association (AUA) Stage D2 disease (45.5%) compared with those with Stage D1 disease (33.3%), Stage C disease (16.7%), Stage A/B disease (18.8%), PIN (25.9%), and BPH (17.0%) (P < 0.02). Supranormal NSE did not change in any of the patient subgroups. Elevated CgA was observed in 36.0% of patients with metastases who had hormone-naive disease and in 45.0% of patients with hormone-refractory disease (P value not significant). Supranormal NSE and CgA values were predictors for poor prognosis in patients with hormone-refractory disease. Elevated baseline CgA values decreased > 50% in 1 of 12 patients who received luteinizing hormone-releasing hormone analogs and in 2 of 12 patients who underwent chemotherapy.

Conclusions: CgA appears to reflect the neuroendocrine activity of PC better than NSE. Elevated CgA values correlate with poor prognosis and are scarcely influenced by either endocrine therapy or chemotherapy.