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Adapted from the NCI Cancer Bulletin, vol. 6/no. 16, August 11, 2009 (see the current issue).
The first large-scale, multi-institution study of prostate cancer mortality since prostate-specific-antigen (PSA) screening has become widely used found that men who undergo prostatectomy have a very high chance of surviving at least 15 years. Among nearly 13,000 patients with a median age of 61, prostate cancer mortality was 12 percent, compared with 38 percent from all causes, according to a July 27, 2009 report in the Journal of Clinical Oncology.
Researchers developed a risk assessment tool to determine each patient's risk of death from prostate cancer according to various clinical factors (such as PSA score) and analysis of the tumor characteristics at biopsy (Gleason score). When patients were stratified into 4 groups according to their calculated risk, 73 percent were in the lowest quartile with only a 5 percent risk of death, and only 2 percent were in the highest quartile with a 38 percent risk.
So many men faced such a low risk, wrote lead author Dr. Andrew J. Stephenson of the Cleveland Clinic, that "potentially many of these patients may have had a similarly low risk of prostate cancer-specific mortality had they received no treatment." The authors observed that "in the United States, only 2 percent of patients younger than 65 years choose active surveillance," with most opting for radiation and/or surgery. The study did not compare radical prostatectomy with other forms of treatment.
Cases diagnosed more recently had a better outcome, perhaps reflecting more effective prostate screening and treatment methods in recent years, the authors noted. Other factors, such as PSA velocity and body-mass index, had no statistically significant relationship with risk.
As for the most aggressive cancers, the authors acknowledged "the difficulty in identifying patients at substantially increased risk based on clinical factors alone," and called for the development of "novel markers specifically associated with the biology of lethal prostate cancer." |
