A new study reveals that in the prediction of treatment outcome for castration-resistant prostate cancer, a change in circulating tumour cells detection might be more accurate than the change in prostate-specific antigen levels. The findings of this award-winning study were presented at the recent EAU 13th Central European Meeting in Prague.
"The research of the circulating tumour cells (CTC) is of utmost importance, because nowadays there is no reliable marker of both cancer-specific or overall survival in castration-resistant prostate cancer (CRPC) patients," explained the lead author of the study, Dr. Otakar Čapoun, of the Department of Urology at General Teaching Hospital Charles University in Prague, Czech Republic.
"The goal of this study is to assess the possibility of the individualisation of castration-resistant prostate cancer management. In cases with no favourable change in CTC detection during chemotherapy, the early switching to another therapy should be considered," commented Čapoun on the implications of the study, which was supported by the Internal Grant Agency of the Ministry of Health of the Czech Republic.
Protocol of the grant project included the collection of peripheral blood from patients with metastatic CRPC prior to docetaxel therapy and after the fourth cycle of chemotherapy (CTX). Circulating tumour cells were detected by using a method of immunomagnetic separation. In the course of the study multiplex-PCR was performed after cytolysis of CTC and the expression of tumour-associated antigens (PSA, PSMA and EGFR) was quantified.
The methodology of the study was based on verbal evaluation together with a report of the absolute values (ng/ml). The authors recorded the levels of serum PSA (sPSA) and the fragments of respective antigens before and in the course of CTX and compared the values. They also evaluated the correlation between the change of sPSA and expression of CTC antigens during CTX.