Neuroendocrine differentiation after neoadjuvant hormonal treatment in prostate cancer.

AIM: Neuroendocrine (NE) differentiation occurs in various degree in the majority of prostatic adenocarcinomas and it has been correlated with tumor progression and poor prognosis. There is little knowledge about the impact of NE differentiation on tumor response to neoadjuvant hormonal treatment (NHT). The role of NE differentiation as a marker of recurrence after radical prostatectomy (RP) is also unclear. We evaluated whether there is an increase in NE differentiation during the course of NHT and whether the tumor relapse after radical surgery correlates with the extent of NE differentiation. METHODS: RP specimens from 44 patients submitted to 3 months of NHT and RP specimens from 40 nonpretreated patients were histologically assessed. Staining for NE differentiated prostate tumor cells was carried out using a specific monoclonal antibody against chromogranin A (CgA). RESULTS: CgA positive cells were found in 4 of 40 patients (10\%) in the RP group and in 4 of 44 patients (9\%) of the NHT+RP group. At follow-up, we had 21 biochemically relapsed patients. Among them, 6 were CgA positive (75\% of 8 patients), whereas is were CgA negative (20\% of 76 patients). CONCLUSIONS: The NE differentiation doesn't increase after NHT. Although not statistically significant a trend to higher risk of relapse among the chromogranin positive samples was observed. The significance of NE differentiation in the progression of the disease and its relation to other known prognostic factors remains unclear.