Circulating Tumor Cell Count Predicts Prostate Cancer Outcome Better Than PSA Measurement Does

A recent paper compared measurement of circulating tumor cells (CTCs) to determination of prostate specific antigen (PSA) for prognosis of survival and drug response in patients with prostate cancer.

The study, which was conducted by investigators at the University of Southern California (Los Angeles, USA), was carried out on blood samples from 263 prostate cancer patients enrolled in phase III clinical trial of a chemotherapeutic approach comprising docetaxel plus prednisone with or without atrasentan.

Baseline PSA levels and CTC counts were determined before start of chemotherapy and were followed for the next three weeks. CTC counts were determined using the Janssen Diagnostics, LLC (Raritan, NJ, USA) CellSearch system. The (US) Food and Drug Administration approved CellSearch System employs unique immunomagnetic and fluorescence imaging technology to provide rapid, precise, and reproducible analysis of CTCs with a simple three-step process that comprises sample collection, sample preparation, and sample analysis. System components include: proprietary CellSave preservative sample tubes, CellSearch CTC Test and Control kits, automated CellTracks Autoprep system, and the CellTracks Analyzer II instrument.

Results obtained during the study validated the prognostic utility of CTC enumeration. Baseline CTC counts were prognostic and rising CTCs at three weeks heralded significantly worse overall survival, potentially serving as an early indicator to help redirect and optimize therapy in this clinical setting.

“The significance of these findings is that looking at CTCs before and three weeks after the first cycle of chemotherapy is an early indicator of whether these men would do well with treatment and how long they may live,” said first author Dr. Amir Goldkorn, assistant professor of medicine at the University of Southern California. “This could help guide clinicians’ treatment decisions and save patients from toxic treatment that will not help them.”

The study comparing determination of CTC counts to PSA measurements was published in the March 10, 2014, online edition of the Journal of Clinical Oncology.

Related Links:
University of Southern California
Janssen Diagnostics, LLC