ORLANDO, FL, USA (UroToday.com) - Circulating tumor cells (CTC) have been shown to provide prognostic information in patients with castration-resistant prostate cancer (CRPC). In addition to serum PSA decline, Dr. Fleisher et al. assessed the response of CTC in patients with metastatic CRPC treated with abiraterone acetate (AA) who had previously failed docetaxel therapy.
At total of 48 metastatic CRPC patients were treated with AA in this study. The median age, base line serum PSA and baseline CTC was 70 years (IQR: 63-79), 99.9 ng/ml (IQR: 36.4-343) and 17 (IQR: 4-49). Baseline CTC count was >5 in 35 patients and 13 patients had < 5 CTC. A decline in baseline CTC from > 5 to < 5 on AA therapy was associated with a decline in PSA by > 50% (p<0.001).
Changes in CTC counts in this study were associated with significant drops in serum PSA for metastatic CRPC on AA therapy. CTC may represent a measurable surrogate for clinical endpoints for metastatic CRPC studies. A Phase III trial is currently underway testing pre and post-therapy CTC and clinical outcomes for CRPC patients who have received docetaxel based chemotherapy.
Presented by M. Fleisher, MD, et al. at the 45th Annual Meeting of the American Society of Clinical Oncology (ASCO) - May 29 - June 2, 2009 - Orange County Convention Center, Orlando, Florida USA.
Written by UroToday.com Contributing Medical Editor Thomas J. Guzzo, MD, MPH, James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions.
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