Cancer-specific and other-cause mortality after radical prostatectomy versus observation in patients with prostate cancer: competing-risks analysis of a large North American population-based cohort

Eur Urol. 2011 Nov;60(5):920-30. doi: 10.1016/j.eururo.2011.06.039. Epub 2011 Jun 29.

Abstract

Background: Initial treatment options for low-risk clinically localized prostate cancer (PCa) include radical prostatectomy (RP) or observation.

Objective: To examine cancer-specific mortality (CSM) after accounting for other-cause mortality (OCM) in PCa patients treated with either RP or observation.

Design, setting, and participants: Using the Surveillance Epidemiology and End Results Medicare-linked database, a total of 44 694 patients ≥65 yr with localized (T1/2) PCa were identified (1992-2005).

Intervention: RP and observation.

Measurements: Propensity-score matching was used to adjust for potential selection biases associated with treatment type. The matched cohort was randomly divided into the development and validation sets. Competing-risks regression models were fitted and a competing-risks nomogram was developed and externally validated.

Results and limitations: Overall, 22,244 (49.8%) patients were treated with RP versus 22450 (50.2%) with observation. Propensity score-matched analyses derived 11,669 matched pairs. In the development cohort, the 10-yr CSM rate was 2.8% (2.3-3.5%) for RP versus 5.8% (5.0-6.6%) for observation (absolute risk reduction: 3.0%; relative risk reduction: 0.5%; p<0.001). In multivariable analyses, the CSM hazard ratio for RP was 0.48 (0.38-0.59) relative to observation (p<0.001). The competing-risks nomogram discrimination was 73% and 69% for prediction of CSM and OCM, respectively, in external validation. The nature of observational data may have introduced a selection bias.

Conclusions: On average RP reduces the risk of CSM by half in patients aged ≥65 yr, relative to observation. The individualized protective effect of RP relative to observation may be quantified with our nomogram.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Chi-Square Distribution
  • Cohort Studies
  • Decision Support Techniques
  • Humans
  • Logistic Models
  • Male
  • Nomograms
  • North America / epidemiology
  • Patient Selection
  • Propensity Score
  • Prostatectomy / mortality*
  • Prostatic Neoplasms / mortality*
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / surgery*
  • Risk Assessment
  • Risk Factors
  • SEER Program
  • Survival Analysis
  • Time Factors
  • Treatment Outcome
  • Watchful Waiting*