Radical prostatectomy for localized cancer extended life span compared to watchful waiting
The amount of absolute benefit from surgery depended on the baseline risk defined by extracapsular extension and a Gleason score higher than 7, according to long-term follow-up data from a Scandinavian study.
Men with clinically detected, localized prostate cancer and a long life expectancy benefited from radical prostatectomy, with a mean of 2.9 years of life gained after 23 years of follow-up, a Scandinavian study found.
The Scandinavian Prostate Cancer Group Study Number 4 randomly assigned 695 men with localized prostate cancer to watchful waiting or radical prostatectomy from October 1989 through February 1999 and collected follow-up data through 2017. Results were published in multiple articles between 2002 and 2014. This follow-up study was conducted 29 years after the start of the trial and was published by the New England Journal of Medicine on Dec. 13.
By December 2017, a total of 261 of the 347 men in the radical prostatectomy group and 292 of the 348 men in the watchful waiting group had died. There were 71 deaths in the radical prostatectomy group and 110 in the watchful waiting group due to prostate cancer (relative risk, 0.55 [95% CI, 0.41 to 0.74; P<0.001]; absolute difference in risk, 11.7 percentage points [95% CI, 5.2 to 18.2 percentage points]). The number needed to treat to prevent one death from any cause was 8.4. At 23 years of follow-up, a mean of 2.9 extra years of life were gained with radical prostatectomy, the authors found.
Among men who underwent radical prostatectomy, extracapsular extension was associated with a fivefold increase in the risk for death from prostate cancer. A Gleason score higher than 7 was associated with a 10-fold increase in risk compared to a score of 6 or lower (scores range from 2 to 10, with higher scores indicating more aggressive cancer).
The benefit of radical prostatectomy in otherwise healthy men can be substantial, the authors said, although they acknowledged that the mean number of years gained is a crude measure, since any man randomly assigned to prostatectomy might not benefit at all or might benefit much more than the group as a whole. However, they continued, the measure puts in perspective what is risked by delaying intervention.
“When our results are applied to inform current practice, several issues have to be considered: the lead time induced by screening, the addition to modern cohorts of overdiagnosed nonlethal cancers, and the influence of modern diagnostics on the definition of risk groups,” the authors wrote. “Furthermore, even if the relative risks in our trial were fully applicable to modern studies, the amount of absolute benefit is highly dependent on baseline risk.”