RESUMO
PURPOSE: The neuroendocrine cell(NEC) is one of the constitutional cells found in the prostate gland; these cells secret neurotransmitters. These neuroendocrine products have been associated with prostate cancer progression. We evaluated the significance of neuroendocrine differentiation(NED) in radical prostatectomy specimens. MATERIALS AND METHODS: We studied 45 patients who underwent bilateral pelvic lymphadenectomy and radical prostatectomy. The patients were classified into three groups according to their pathological stage. Group A included cases with organ confined tumors, Group B local advanced tumors and Group C cases had any T stage and lymph node metastasis. The cellular expression of chromogranin A in matched samples from the same patients was evaluated by immunohistochemical staining using commercially available monoclonal antibodies. RESULTS: Sixteen(35.6%) tumors had chromogranin A stained cells. Chromogranin A immunoreactivity was greatest in cases with lymph node involvement(75.0%) compared to those with primary prostate cancer(5.9% in group A and 37.5% in group B). Pathologically advanced tumors or tumors with the highest histological grades were associated with increased NED. The median staining score was 0 in Group A, 0 in Group B and 1 in Group C. The logistic regression analysis the odds ratio for group C cases showed a relative risk of 32.07(95% CI: 2.783-369.416) for NED compared to Group A. An increased prostate-specific antigen(PSA) and Gleason score were also associated with the NED. CONCLUSIONS: The degree of NEC immunohistochemical staining using the chromogranin A monoclonal antibody was marginally useful for predicting the outcome in prostate cancer patients after radical prostatectomy, especially in node positive patients. However, it is important to determine a therapeutic plan for patients with low PSA and internal organ metastasis.