MINNEAPOLIS —Because very long-term mortality in men with early prostate cancer treated with surgery over observation is uncertain, a VA study sought to determine long-term effects of surgery vs. observation on all-cause mortality for men with early prostate cancer.
With results published in the journal European Urology, the research evaluated long-term follow-up of a randomized trial conducted at VA and National Cancer Institute sites.1
Participants in the study led by the Minneapolis VAMC and the University of Minnesota were 731 men 75 and older with localized prostate cancer, prostate-specific antigen less than 50ng/ml, life expectancy of 10 years or more and who were medically fit for surgery.
The team compared the use of radical prostatectomy to observation.
Over 22.1 years (median follow-up for survivors=18.6yr; interquartile range: 16.6-20.0), 515 men died, according to the results. Researchers noted that 246 of 346 men (68%) were assigned to surgery vs. 269 of 367 (73%) assigned to observation (hazard ratio 0.84 [95% confidence interval {CI}: 0.70-1.00]; p= 0.044 [absolute risk reduction = 5.7 percentage points, 95% CI: -0.89 to 12%]; relative risk: 0.92 [95% CI: 0.84-1.01]).
The authors pointed out that the restricted mean survival in the surgical group was 13.6 years (95% CI: 12.9-14.3) vs. 12.6 years (95% CI: 11.8-13.3) in the observation group, so that, essentially, a mean of one life-year was gained with surgery.
“Results did not significantly vary by patient or tumor characteristics, although differences were larger favoring surgery among men aged <65 yr, of white race, and having better health status, fewer comorbidities, ≥34% positive prostate biopsy cores, and intermediate-risk disease,” according to the authors, who added that results were not adjusted for multiple comparisons, so they could not assess outcomes other than all-cause mortality.
Noting that surgery was associated with small very long-term reductions in all-cause mortality and increases in years of life gained, researchers emphasized that absolute effects did not vary markedly by patient characteristics. They explained, however, that absolute effects and mean survival were much smaller in men with low-risk disease but were greater in men with intermediate-risk disease, although not in those with high-risk disease.
“Strategies are needed to identify men needing and benefitting from surgery while reducing ineffective treatment and overtreatment,” the authors concluded.
- Wilt TJ, Vo TN, Langsetmo L, et al. Radical Prostatectomy or Observation for Clinically Localized Prostate Cancer: Extended Follow-up of the Prostate Cancer Intervention Versus Observation Trial (PIVOT) [published online ahead of print, 2020 Feb 21]. Eur Urol. 2020;S0302-2838(20)30115-9. doi:10.1016/j.eururo.2020.02.009