Comorbidity and mortality results from a randomized prostate cancer screening trial

Abstract

Purpose: Estimates of prostate cancer-specific mortality (PCSM) were similar for men randomly assigned to intervention compared with usual care on the Prostate, Lung, Colorectal and Ovarian PC screening study. However, results analyzed by comorbidity strata remain unknown.

Patients and methods: Between 1993 and 2001, of 76,693 men who were randomly assigned to usual care or intervention at 10 US centers, 73,378 (96%) completed a questionnaire that inquired about comorbidity and prostate-specific antigen (PSA) testing before random assignment. Fine and Gray's multivariable analysis was performed to assess whether the randomized screening arm was associated with the risk of PCSM in men with no or minimal versus at least one significant comorbidity, adjusting for age and prerandomization PSA testing.

Results: After 10 years of follow-up, 9,565 deaths occurred, 164 from PC. A significant decrease in the risk of PCSM (22 v 38 deaths; adjusted hazard ratio [AHR], 0.56; 95% CI, 0.33 to 0.95; P = .03) was observed in men with no or minimal comorbidity randomly assigned to intervention versus usual care, and the additional number needed to treat to prevent one PC death at 10 years was five. Among men with at least one significant comorbidity, those randomly assigned to intervention versus usual care did not have a decreased risk of PCSM (62 v 42 deaths; AHR, 1.43; 95% CI, 0.96 to 2.11; P = .08).

Conclusion: Selective use of PSA screening for men in good health appears to reduce the risk of PCSM with minimal overtreatment.

Fig 1.

(A) Unadjusted cumulative incidence estimates of prostate cancer incidence in men with no or minimal comorbidity randomly assigned to usual care or intervention. k-sample P = .04. (B) Unadjusted cumulative incidence estimates of prostate cancer incidence in men with at least one significant comorbidity randomly assigned to usual care or intervention. k-sample P < .001.

Fig 2.

(A) Unadjusted cumulative incidence estimates of prostate cancer–specific mortality in men with no or minimal comorbidity randomly assigned to usual care or intervention. k-sample P = .03. (B) Unadjusted cumulative incidence estimates of prostate cancer–specific mortality in men with at least one significant comorbidity randomly assigned to usual care or intervention. k-sample P = .07. Bonferroni adjustment for a significant P value was < .05 ÷ 2 or .025.