Neuroendocrine differentiation in prostatic adenocarcinoma and its relationship to tumor progression.

Background: Neuroendocrine differentiation has been demonstrated by immunohistochemical preparations in many cases of acinar type prostatic adenocarcinoma (CAP). Some studies have suggested that this differentiation may indicate an adverse prognosis.
Methods: Tissue samples from 38 consecutive patients with clinical Stage II (AJCC) CAP who underwent radical retropubic prostatectomy (RRP) were studied after preparations were made with antichromogranin (ChA) and neuron-specific enolase (NSE). All patients were followed for at least 4 years post-RRP or until disease progression was documented by rising serum prostate specific antigen concentration, X-ray evidence of recurrence, or a positive tissue biopsy.
Results: Nine of the 38 RRP specimens (24%) were positive for NSE, and 11 (29%) were positive for ChA. Neither of these neuroendocrine markers showed a significant correlation with tumor progression. Neuroendocrine differentiation in needle biopsy specimens from these same patients (when available) did not correlate with tumor progression either. Of the patients with tumor progression, 9 of 11 (82%) had pathologic Stage III disease after RRP; of those with no progression of CAP, only 7 of 27 (26%) had pathologic Stage III disease.
Conclusions: Neuroendocrine differentiation, as demonstrated by NSE and ChA preparations, was not helpful in predicting tumor progression of CAP.