Abstract
Purpose Approximately 50 percent of all malignant prostatic tumors contain neuroendocrine cells, which cannot be attributed to small cell prostatic carcinoma or carcinoid-like tumors, and which represent only 1 to 2 percent of all prostatic malignancies. Only limited data are available concerning the plasma levels of neuroendocrine markers in patients with prostatic tumors. Therefore, we determined the incidence of high plasma levels of neuroendocrine markers in patients with benign and malignant prostatic disease. Materials and Methods The presence of elevated plasma neuropeptide levels was investigated in 135 patients with prostatic carcinoma and 28 with benign prostatic hyperplasia. Plasma chromogranin A, neurone-specific enolase, substance P, calcitonin, somatostatin, neurotensin and bombesin levels were analyzed by immunoassays, and were compared to clinical and pathological stages of disease. Plasma prostatic acid phosphatase and prostate specific antigen levels were also determined. All patients were followed for at least 2 years after inclusion in the study. Results Significantly elevated levels of chromogranin A were detected in 15 percent of patients with prostatic carcinoma before any treatment. During hormone resistant prostate cancer progression plasma chromogranin A and neuron-specific enolase levels were elevated in 55 percent and 30 percent of the patients, respectively. In patients with stage D3 disease survival curves were generated by the Kaplan-Meier method, and log rank analysis revealed a statistically significant difference between groups positive and negative for chromogranin A. Substance P and bombesin were also occasionally elevated in prostatic tumors. Determination of neuroendocrine differentiation by neuron-specific enolase or chromogranin A immunoassays was not helpful in the prediction of progressive localized prostatic carcinoma. Conclusions Future studies of plasma neuropeptide levels should confirm whether these parameters can be used as prognostic markers during late progression of prostatic carcinoma or for the selection of patients suitable for evaluation of new antineoplastic drugs known to be active against neuroendocrine tumors.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have