New tools show value in predicting post-treatment prostate cancer risk

Two new methods for evaluating prostate cancer risk following primary treatment have shown promise in separate studies.

The University of California, San Francisco Cancer of the Prostate Risk Assessment (CAPRA), a preoperative risk stratification index that produces an easily calculated score from 0 to 10 to predict the likelihood that men will experience PSA recurrence after surgery, performed as well as the best available risk prediction systems based on a number of preoperative variables, including age, PSA, Gleason grade, tumor stage, and percent of biopsy cores positive, according to a multi-institutional study published in Cancer (2006; 17:2384-91).

“The goal was to devise a scoring system that would perform as well as the best available instruments for prediction of biochemical recurrence after prostate surgery, yet would be easier to calculate,” said lead author Matthew Cooperberg, MD, of UCSF.

Data for 1,346 men with localized prostate cancer who had undergone prostatectomy between 1988 and 2004 were abstracted from a database of 2,096 men and were used to calculate the CAPRA score. Using multivariate analysis to assess biological and pathologic outcomes, researchers found that 26% of eligible patients experienced recurrence after surgery, and that as CAPRA scores increased, the risk of adverse pathologic outcomes increased significantly.

In related news, a new classification system for evaluating men after radiation treatment for prostate cancer better determines which men may experience disease recurrence and who might benefit from hormone therapy, according to a study from Fox Chase Cancer Center, Philadelphia. Results of a study applying the new system, called the Phoenix definition, were presented at the annual meeting of the American Society for Therapeutic Radiology and Oncology in Philadelphia.

“The Phoenix system allows a more robust prediction for clinical outcome,” said co-author Matthew C. Abramowitz, MD. “By using the new classification system, we’ve been able to better identify patients who could benefit from hormone intervention.”

Dr. Abramowitz and colleagues applied the Phoenix system of defining biochemical failure to 1,831 previously treated patients. The new biochemical failure definition could alter the course of treatment, which may include hormone therapy sooner and for more men. The study demonstrated a significant improvement in predicting endpoints, including distant metastasis, cause-specific mortality, and overall mortality.