Abstract
Castration resistant prostate cancer (CRPC) in an advanced stage of prostate cancer with very poor prognosis for the patient. One of the main characteristics of this disease is a presence of metastases mainly in bones.
Circulating tumor cells (CTCs) as an integral part of metastatic process are present in the blood of majority of the patients with CRPC. For this reason we would like to figure out if CTCs are relevant prognostic or therapy efficiency marker We drawn samples from CRPC patients at the time of diagnosis and after the 4th cycle of chemotherapy.
Five ml of peripheral blood was used for immunomagnetic separation (Adnagen, Germany). Form isolated mRNA the presence of tumor-associated genes (PSA, PSMA, EGFR) was determined by using PCR methods and capillary electrophoresis on Agilent Bioanalyzer 2100.
Until now, we tested twice 16 patients with CRPC and more is waiting for the second test. 85% of the patients are CTCs positive at the time of CRPC diagnosis. After the therapy only 44% of the patients remained CTCs positive and 95% showed decrease of the monitored markers.
The presence of individual markers differs between the patients. Based on the CTCs examination we are able to create subgroups of patients which respond to the therapy differently.
The future will show whether also the prognosis in these patients differs. Our current data indicate that CTCs could serve as a therapy efficiency marker, and possibly as a prognostic marker for patient with CRPC.