"It makes two very important points," Zelefsky said. "One is that in order to achieve optimal results, you have to give salvation radiotherapy sooner rather than later, before two years have elapsed. After two years, the results are less optimal.
"Second, the surprising thing to come out of the study is about people who have rapid PSA doubling time. Normally, you think of those patients as having more aggressive disease that has spread elsewhere. This suggests otherwise, that even though the doubling time is more rapid, you still get excellent outcomes with radiotherapy."
Cancer specialists might have to start thinking differently about such cases, Zelefsky said. "People usually have a fatalistic approach when it comes to those patients who present with recurrence and a rapid PSA doubling time," he said. "Now, you might be able to cure them."
It is hard to say whether the report will have an immediate impact on medical practice, both Trock and Zelefsky said. "The study needs to be validated in a formal, randomized controlled trial," Zelefsky said.
But such a study might be beyond the capability of an individual cancer center, Trock said. "You would need at least one or more large institutions with large data bases to validate our results," he said.
Facts on the incidence and treatment of prostate cancer are available from the National Cancer Institute.
SOURCES: Bruce J. Trock, Ph.D., associate professor, urology, Johns Hopkins University, Baltimore; Michael J. Zelefsky, M.D., professor, radiation oncology, Memorial Sloan-Kettering Cancer Center, New York; Jun
All rights reserved