The study examines survival data of more than 48,606 men between 65 and 80 years old who survived at least one year after a diagnosis of localized prostate cancer (cancer that has not spread beyond the prostate).
Since the advent of the PSA (prostate-specific antigen) blood test about 20 years ago, many more cases of prostate cancer have been diagnosed at earlier stages.
"Some prostate cancers grow so slowly that they never become life-threatening, especially in elderly men who may die of other causes before the cancer causes problems," explained Wong. "But other men develop complications and die from their cancer making the decision to treat quite difficult."
It remains unclear whether detecting early prostate tumors translates into an equivalent benefit of saving lives and whether the benefits of early detection outweigh the risks of complications from follow up diagnostic tests and cancer treatments.
The cases examined in this study were diagnosed between 1991 and 1999. The men ranged from 65 to 80 years old at diagnosis. Median age at diagnosis was 72. A total of 34,046 men received treatment with either radiation therapy (19,948) or surgery--radical prostatectomy--to remove the prostate (14,098). The remaining 14,560 men were only observed (watchful waiting).
More than half the treated men were alive by the end of the study, with a median survival of 13 years. Median survival for the group receiving observation was about 10 years.
"This large, population-based study demonstrates a survival advantage for men treated with either radical prostatectomy or radiation therapy compared to observation," Wong said. "Eligible men should be considered for both treatment options."