Prostate cancer and neuroendocrine differentiation.

A retrospective study was conducted in 41 patients with adenocarcinoma of the prostate to investigate the correlation between pathological stage, Gleason score and neuroendocrine differentiation in order to evaluate the prognostic significance of neuroendocrine differentiation. Patients' ages ranged from 50 to 84 (mean 69.1) years. Clinical staging was done by rectal examination, serum PSA, transrectal ultrasonography, bone scan and abdominal CT followed by pathological staging after the operation. After that malignant prostatic tissue sections obtained from radical prostatectomy and transurethral prostatectomy specimens were stained with haemotoxylin-eosin and Gleason scores were determined. From each patient paraffin blocks representative of the primary prostate adenocarcinoma were chosen for immunohistochemical staining with monoclonal neuron specific enolase and chromogranin A antibodies for the determination of neuroendocrine differentiation. Neuroendocrine cells were found to be present in 53.66% of the patients. The incidence of neuroendocrine differentiation was higher in poorly differentiated (Gleason 7-10) tumours when compared to moderately and well differentiated tumours (Gleason <7) although not statistically significant (p=0.09). Although the percentage of neuroendocrine differentiation was greater in advanced prostate carcinoma (stage C, D) than localized (stage A, B) the difference was not statistically significant (p=0.18). Nevertheless, a significant correlation was present between Gleason score and pathological stage (p=0.002). In 34 cases followed for 5 years there was no relationship between the presence of neuroendocrine cells and 5-year tumour progression (p=0.41). However, significant increase in tumour progression rate was observed with increase in Gleason score (p=0.02) and pathological stage (p=0.00001). As a conclusion, no significant correlation was found between neuroendocrine differentiation and prognostic markers such as Gleason score and pathological stage in adenocarcinoma of the prostate.