Research published in JAMA Oncology on Thursday revealed that higher doses of radiation don’t improve survival for many prostate cancer patients, compared with standard radiation treatment.
“Over the past two decades radiation oncologists have become adept at treating men to these higher radiation doses, as long as they respect normal tissue tolerances,” Dr. Jeff M. Michalski, professor at the University of Washington School of Medicine, told HCB News. “I believe we will continue to see this approach, but physicians will not be aggressively taking risks knowing that it won’t benefit their patient to increase their possibility of side effects.”
For the study, Michalski and his team evaluated 1,500 patients with intermediate-risk prostate cancer. The patients were split into two groups – 748 received standard treatment and 751 received dose-escalation treatment.
They did observe significantly lower rates of recurrence, tumor growth and metastatic disease in the group that received high doses of radiation, but there was no significant difference in survival. After eight years of follow-up, 75 percent of the standard treatment group and 76 percent of the dose-escalation treatment group were still alive.
Since prostate cancer is common in older men, most of the deaths in the trial population were caused by things other than prostate cancer. In addition, six new therapies were approved for recurrent or metastatic prostate cancer during the study period that have been shown to improve survival.
Michalski believes that higher doses of radiation should be avoided if the clinician is unable to safely deliver it. For instance, if the patient’s rectum or bladder can be spared well enough, high doses shouldn’t be used.
“We also need to better identify the patient populations that might benefit from improvements in local therapy,” said Michalski. “The next generation of NRG trials are using genomic testing to better identify patients that are at a risk of death from prostate cancer.”
