A new classification system for evaluating men after radiation treatment for prostate cancer better determines which men may recur and thus may benefit from hormone therapy. The results of a study applying the new system were presented today at the 48th Annual Meeting of the American Society for Therapeutic Radiology and Oncology in Philadelphia.
Men at risk of having their prostate cancer recur are often offered hormone therapy to control their cancer. Given as an injection, this therapy suppresses hormones in the body thought to fuel the growth of the disease. Physicians determine who will benefit from hormone therapy by considering many factors, including biochemical failure (BF).
BF, which indicates treatment failure, is determined with a calculation involving post-treatment PSA levels. (PSA, or prostate specific antigen, is measured by a blood test and used to determine if prostate cancer is present.) A new classification system, called the Phoenix definition, changes the method of determining BF failure and provides a better evaluation method for predicting a patient's outcome.
"The Phoenix system allows a more robust prediction for clinical outcome," said Matthew C. Abramowitz, M.D., a resident in the radiation oncology department at Fox Chase Cancer Center. "By using the new classification system, we've been able to better identify patients who could benefit from hormone intervention. "Under the previous classification system, these men may have been misclassified. Using the new definition, we are able to better identify those men most likely to develop problems from their recurrent prostate cancer. These men may benefit from hormone therapy."
Abramowitz and his colleagues applied the Phoenix system of defining biochemical failure to 1,831 previously treated patients. The new BF definition could alter the course of treatment, which may include hormone therapy sooner and for more men. The study demonstrates a significant improvement in predicting endpoints, including distant metastasis, cause-specific mortality and overall mortality.
"Our study shows that treating prostate cancer aggressively and preventing biochemical failure could translate into improved disease-free and overall survival for more men," Abramowitz concluded.