Circulating chromogranin a and hormone refractory prostate cancer chemotherapy

PURPOSE: Neuroendocrine differentiation is a frequent pattern in prostate adenocarcinoma. CgA seems to be a useful indicator of neuroendocrine differentiation in patients with HRPC. We evaluated the clinical interest of circulating CgA in HRPC. MATERIALS AND METHODS: Serum CgA was assessed by immunoradiometric assay in 39 patients with HRPC treated with paclitaxel and carboplatin or mitoxantrone. Baseline CgA and its variation during chemotherapy were studied. RESULTS: Increased serum CgA was observed in 45% of patients. Previous local radiotherapy and the duration of hormonal therapy were independent factors that influenced CgA. There was no correlation between CgA and prostate specific antigen. Increased serum CgA showed positive predictive significance but no prognostic value. The chemotherapy response correlated with a CgA decrease of greater than 25%. CONCLUSIONS: The current study suggests that CgA assessment facilitates patient selection by predicting the chemotherapy response and providing complementary information to follow the chemotherapy response.