Chromogranin a concentration as a serum marker to predict prognosis after endocrine therapy for prostate cancer

Purpose: Chromogranin A is gaining acceptance as a serum marker of neuroendocrine tumors and the concentration is thought to be elevated in relation to neuroendocrine differentiation of prostate cancer. We examined the significance of the chromogranin A level as a serum marker for prostate cancer. Materials and Methods: Serum chromogranin A values were determined by monoclonal immunoradiometric assay in 108 patients with prostate cancer before treatment and in 66 with benign prostatic hyperplasia. In those with prostate cancer clinicopathological parameters, the response to endocrine therapy and the prognosis were evaluated in relation to serum chromogranin A. Results: Mean serum chromogranin A plus or minus standard deviation in prostate cancer and benign prostatic hyperplasia cases was 59.4 +/- 52.5 and 59.3 +/- 44.3 ng/ml., respectively (not significant). Poorly differentiated adenocarcinoma was associated with higher chromogranin A than well differentiated disease (p = 0.044). Of the stage D cases with a median prostate specific antigen (PSA) of 172.1 ng/ml. or less those with higher chromogranin A had a poorer prognosis than those with lower chromogranin A. In contrast, in stage D cases with a PSA of greater than 172.1 ng/ml. there was no difference in the prognosis between the higher and lower chromogranin A groups. Conclusions: Serum chromogranin A tends to be elevated in patients with high grade prostate cancer. When combined with PSA, this marker may effectively predict a poor prognosis after endocrine therapy.