Serum chromogranin-A in advanced prostate cancer

Objective To determine the value of serum chromogranin A (CgA), a marker of neuroendocrine differentiation. for monitoring prostate cancer: CgA levels were related to three other tumour markers. i.e. total prostate-specific a ntigen (tPSA). prostatic acid phosphatase (PAP). neurone-specific enolase ( NSE), and to testosterone. to assess the importance of hormone withdrawal. Patients and methods Serum samples (218) were obtained from 118 patients wi th prostate cancer. including 111 patients with advanced prostate cancer: 1 03 presented to our centre for systemic radionuclide therapy of painful ske letal metastases. CgA concentrations were measured using a new immunoradiom etric assay (IRMA: Cis Bio International. Gif sur Yvette. France) and a thr eshold of 70 ng/mL was determined after receiver operating characteristic c urve analysis. Testosterone was also measured with an IRMA assay: tPSA, PAP and NSE were assayed using the time-resolved amplified cryptate emission. Results Serum marker levels were high in 64% of the patients for CgA. 24%, for NSE. 89%, for tPSA and 81%, for PAP. Patients resistant to endocrine tr eatments and with elevated tPSA (i.e. hormone-independent) showed increased CgA and NSE in 62% and 29%, respectively. Patients xvith hormone-dependent prostate cancer (i.e. with a normal tPSA level) had elevated CgA in 59% bu t no abnormal NSE. All patients of the latter group except one showed clini cal progression of their disease. However. the mean (SD) concentrations of CgA in hormone-independent (146) or hormone-de pendent (22) patients, at 18 5.3 (449.1) and 160.9 (293.9) ng/mL, respectively. were not statistically d ifferent (P = 0.8, Mann-Whitney U-test). For 30 patients, blood samples wer e drawn and markers measured before and after systemic radionuclide therapy . There was a significant increase in the CgA and tPSA concentrations after treatment (P=0.0146 and 0.0025. respectively). Conclusions In association with tPSA. serum CgA appears to be a promising m arker for monitoring patients with prostate cancer.