[Relationship of neuroendocrine differentiation to biological behavior of prostate cancer]

To investigate the relationship between neuroendocrine differentiation (NED) in prostate cancer and hormone refractory prostate cancer.

Fifty-five prostate cancer specimens were obtained from 55 patients following intermittent androgen blockade during operation of transurethral resection of prostate. Monoclonal antibody immunohistochemistry was used to detect the expression of chromogranin A (CgA), a specific marker of neuroendocrine cell in the specimens. Follow-up was conducted for 25 (5 - 85) months. Serum prostate specific antigen (PSA), bone scan, chest X-ray, and computerized tomography were performed regularly during follow-up.

Twenty-six of the 55 specimens (47.3%) were positive in CaG, and 23 of the 35 tumors with the Gleason score >or= 7 was 66%, significantly higher than those of the lower-grade tumors (all P < 0.01). Most of the high-grade tumors showed small cluster pattern, and most of the low-grade tumors showed solitary scattered pattern. The numbers of NED cells in the stage III and IV tumors were 67% and 71.4% respectively, both significantly higher than that of the stage II tumors (25%, both P < 0.05), There was no correlation between the NE positive cell rate and preoperative PSA value (P > 0.05). Thirty cases progressed to a hormone-independent status within 18 (5 - 79) months (Group A), and the rest 25 cases remained not progressing within 31 (17 - 85) months (Group B). The NED rate of Group A was significantly higher than that of Group B (P < 0.05). Univariate analysis showed that NE positivity, Gleason >or= 7, stage IV, and bone metastasis were influential factors of clinical progression. Multivariate COX regression analysis showed that NED and pre-operational PSA value were independent prognostic factors of bone metastasis.

NED is associated with poor prognosis and hormone refractory prostate cancer in patients with androgen deprivation therapy.