Prognosis of Castration-resistant Prostate Cancer Patients - Use of the AdnaTest® System for Detection of Circulating Tumor Cells.

Background: Detection of circulating tumor cells (CTC) in patients with castration-resistant prostate cancer (CRPC) may improve the estimate of chemotherapy response. We evaluated the AdnaTest (R) system in patients receiving docetaxel. Patients and Methods: CTC analysis was carried out in 37 patients by immunomagnetic separation. Correlation between serum prostate-specific antigen (sPSA) change and CTC presence and the influence of each parameter on the overall survival (OS) were evaluated. Results: We detected CTCs in 32 and 16 patients before and after three docetaxel cycles, respectively. The sPSA level correlated with CTC positivity during docetaxel therapy (p=0.0031). The longest OS was in patients negative for CTCs in both samples (p=0.0228). Change in sPSA levels was associated with treatment response (p=0.033). Conclusion: We detected CTCs in a considerable munber of patients with CRPC. The absolute change of sPSA level correlated with OS. CTC presence during docetaxel therapy was associated with shorter OS.