UPPSALA, SwedenIn a new study, radical prostatectomy reduced deaths due to prostate cancer but did not increase overall survival in men with newly diagnosed, early-stage disease. The Scandinavian Prostatic Cancer Study Group found that after a median 6.2 years of follow-up, there were no significant differences in overall survival, but patients randomized to radical prostatectomy were less likely to develop distant metastases than those randomized to watchful waiting.
The survival and quality-of-life analyses were reported in the September 12 New England Journal of Medicine. Lead author on the survival analysis is Lars Holmberg, MD, PhD. Lead author on the quality-of-life analysis is Gunnar Steineck, MD.
The study, which was initiated before the era of routine prostate-specific antigen (PSA) testing, enrolled 695 men with clinical stage T1b, T1c, or T2 disease. Anna Bill-Axelson, MD, who is co-author on the Holmberg paper, told ONI that the investigators were quite surprised to see a difference in disease-specific mortality emerge so early in the study.
"The most important clinical implication of our study is that radical prostatectomy reduces the risk of death from prostate cancer by 50%. The study was designed to detect a much smaller difference, and we were surprised that the difference was so prominent after such a short time," said Dr. Bill-Axelson, who is in the Department of Urology, University Hospital, Uppsala, Sweden.
The difference in disease-specific mortality first became apparent after 5 years of follow-up (4.6% with watchful waiting vs 2.6% with radical prostatectomy). At 8 years of follow-up, the prostate cancer death rate was 13.6% with watchful waiting and 7.1% with radical prostatectomy (relative hazard 0.5, 95% CI 0.27 to 0.91, P = .02).
"The relative risk reduction was 50%, which translates into a small absolute reduction, since the risk of death in both groups after this short time is small. We think that only longer follow-up can determine if there will be a benefit in overall survival. The difference at this time is too small to be significant," Dr. Bill-Axelson said.
In an interview with ONI, Eric A. Klein, MD, Section Head for Urologic Oncology, Cleveland Clinic Urological Institute, pointed out that 75% of prostate cancer diagnoses in the United States are in men with nonpalpable disease who have had biopsies because of elevated PSA levels, while only 10% of the patients in the Swedish study were diagnosed at this early stage.