The meta-analysis, which included 2,153 patients followed for an average of five years, found that 88% of men who held off on radiation did not have a relapse, compared to 85% who had radiation soon after surgery. Among those who held off, 67% still didn't need radiation up to eight years later.
Urinary incontinence was worse at one year for men with post-surgical radiation. And 6% of them had difficulty urinating because of damage to a duct called the urethra, compared to 4% of men who postponed radiation.
"The idea was always that you were missing an opportunity" for a cure, Kutikov said. "These studies tell me we can hold off, even in those men" at higher risk of recurrence.