The prognostic value of neuroendocrine differentiation in adenocarcinoma of the prostate in relation to progression of disease after endocrine therapy

Purpose: We evaluated the prognostic impact of neuroendocrine differentiation in prostate cancer with regard to the onset of endocrine therapy failure. Materials and Methods: A retrospective study was performed on 72 transurethral resection specimens from patients who subsequently underwent endocrine therapy for prostate cancer and were followed for 44 to 95 months. Progression-free interval was recorded. Distribution pattern and proportion of neuroendocrine cells were examined in transurethral resection specimens. Neuroendocrine cells were identified based on immunoreactivity for chromogranin A. Results: Of 32 patients with progressive disease 27 died of prostate cancer. Chromogranin A positive cells were found in 40 of the 72 prostate cancers (55%). In a Cox proportional hazards analysis neuroendocrine differentiation of the tumor showed a negative correlation with progression-free survival (p = 0.022), which proved to be independent of the Gleason score (p <0.001). Conclusions: Our results support the view that neuroendocrine differentiation in prostatic adenocarcinomas is a prognostic factor for progressive disease under subsequent endocrine therapy. This prognosticator acts independently of tumor grade.