[Neuroendocrine differentiation and markers of cell proliferation in a group of patients with prostate adenocarcinoma and normal or high serum prostate-specific antigen levels].

Objective: Study the morphologic characteristics of neuroendocrine cells in prostate cancer with normal versus elevated prostate specific antigen (PSA).

Materials And Methods: 372 cases of prostate cancer were identified during a 13 year period, of which 19 displayed normal PSA (group I). Sixteen controls with elevated PSA and similar histopathological characteristics (group II) were included. We studied the degree of tumor necrosis, vascular and perineural invasion. Synaptophysin (SP), neuron specific enolase (NSE), PSA, Ki-67 and p53 inmunoreactivity were also analyzed.

Results: Group I positive findings were 61% PSA, 28.6% SP. 7.1% NSE, 50%p53, and 78.6% Ki-67. Group II positive findings were 93% PSA, 13.3% SP, 26.6% NSE 46.6% p53, and 66.7% Ki-67. When we used a <80% cut off point for PSA immunoreactivity in tumor cells, 69.2% of group I and 21.4% of group II were found.

Conclusions: The sole histopathological finding that showed statistical significance was the tissular expression of the specific prostatic antigen in 80% of neoplasic cells in group I. The increase of neuroendocrine cells was associated with a smaller number of tissular antigen producing cells, a finding that could be more apparent if we were to study a larger sample size.