[Neuroendocrine cancer of the prostate. A series of 6 cases]

Neuroendocrine cancer of the prostate (NECP) is a rare entity. Screening for this tumour, although not systematic, may have therapeutic implications. The authors retrospectively evaluated 6 cases of NECP observed in the department between September 1998 and May 2002.

The diagnosis was based on immunohistochemical analysis of biopsy fragments with the presence of marked neuroendocrine differentiation (minimum 50%). Positive staining for anti-Neuron-Specific Enolase (NSE) and anti-Chromogranin A antibodies was observed in 5 and 6 cases, respectively, while anti-PSA antibody labelling was always negative.

NECP represented 2.1% of all prostate cancers diagnosed in the department over the same period. Digital rectal examination was abnormal in every case with a median PSA of 9.75 ng/ml (range: 0.25-19.6). Three patients presented metastatic disease at the time of the diagnosis. Four of the 6 patients were urgently admitted to hospital because of acute clinical features. Paroxysmal abdominal pain occurred during the course of the disease in every case with a median of 52 days (range: 22-198) and was initially present in 2 cases. Chemotherapy was performed in 3 cases and palliative therapy was administered in the other cases. A survival difference was observed for patients treated by chemotherapy (13 months versus 4.7). The median survival was 9 months and 14 days. Death occurred in a context of rapid alteration of the general state and renal function.

NECP has a poor prognosis. Clinical and complementary features guide the diagnosis, which can be confirmed by immunohistochemical analysis, allowing early management based on chemotherapy.