Seventy-two percent of these men died of other causes or didn't have enough cancer progression to warrant surgery or radiation, the researchers found. For the remaining 2,675 men who did receive treatment, the median time between diagnosis and start of therapy was more than 10 years.
Not surprisingly, men with less aggressive disease survived longer than those with more aggressive tumors.
"For elderly men with localized prostate cancer, the potential survival benefit for treatment is most likely modest, therefore it is very critical to weigh the risk of having side effects of various treatments with the risk of developing cancer-related complications down the road," Lu-Yau said. "The majority of patients will die of other causes or remain alive without significant major complications."
A second study presented at the conference found that giving salvage radiation therapy (SRT) to men whose PSA levels rise after having their prostate removed can reduce their risk of dying from the cancer by more than 60 percent.
SRT is typically given only after a recurrence, not after an initial diagnosis of prostate cancer, noted study lead author Dr. Bruce Trock, associate professor of urology, epidemiology, oncology and environmental health sciences at Johns Hopkins University School of Medicine in Baltimore. Existing studies have either not been large enough or long enough in duration to determine if SRT prolongs survival.
In this retrospective analysis of 635 men who had experienced a recurrence after having their prostate removed, 62 percent of those who did not receive any salvage therapy were still alive after 10 years, versus 86 percent of those who received SRT and 82 percent of those who received SRT plus hormone therapy.
Men whose PSA doubling time (the amount of time it took for PSA levels to double from when in first becomes detectable) was six months or less had the greatest benefit.
"If another study was able to replicate our data, it could lead to clinical trial that would eventually support a way to determine who should get immediate adjuvant radiation and who could wait until the time of recurrence to have SRT," Trock said. "The question is, could a benefit be achieved in some of these men if you waited to see whether they recurred or not?"
More information
There's more on prostate cancer at U.S. National Cancer institute.
