Radical prostatectomy versus observation for localized prostate cancer

Abstract

Background: The effectiveness of surgery versus observation for men with localized prostate cancer detected by means of prostate-specific antigen (PSA) testing is not known.

Methods: From November 1994 through January 2002, we randomly assigned 731 men with localized prostate cancer (mean age, 67 years; median PSA value, 7.8 ng per milliliter) to radical prostatectomy or observation and followed them through January 2010. The primary outcome was all-cause mortality; the secondary outcome was prostate-cancer mortality.

Results: During the median follow-up of 10.0 years, 171 of 364 men (47.0%) assigned to radical prostatectomy died, as compared with 183 of 367 (49.9%) assigned to observation (hazard ratio, 0.88; 95% confidence interval [CI], 0.71 to 1.08; P=0.22; absolute risk reduction, 2.9 percentage points). Among men assigned to radical prostatectomy, 21 (5.8%) died from prostate cancer or treatment, as compared with 31 men (8.4%) assigned to observation (hazard ratio, 0.63; 95% CI, 0.36 to 1.09; P=0.09; absolute risk reduction, 2.6 percentage points). The effect of treatment on all-cause and prostate-cancer mortality did not differ according to age, race, coexisting conditions, self-reported performance status, or histologic features of the tumor. Radical prostatectomy was associated with reduced all-cause mortality among men with a PSA value greater than 10 ng per milliliter (P=0.04 for interaction) and possibly among those with intermediate-risk or high-risk tumors (P=0.07 for interaction). Adverse events within 30 days after surgery occurred in 21.4% of men, including one death.

Conclusions: Among men with localized prostate cancer detected during the early era of PSA testing, radical prostatectomy did not significantly reduce all-cause or prostate-cancer mortality, as compared with observation, through at least 12 years of follow-up. Absolute differences were less than 3 percentage points. (Funded by the Department of Veterans Affairs Cooperative Studies Program and others; PIVOT ClinicalTrials.gov number, NCT00007644.).

Figure 1. Study Enrollment and Treatment

Of a total of 13,022 men who were screened for participation, 5023 were eligible for enrollment; of these, 731 were randomly assigned to radical prostatectomy or observation. Of the 364 men in the radical-prostatectomy group, 287 underwent attempted surgery, as did 37 of the 367 men in the observation group. EBRT denotes external-beam radiotherapy.

Figure 2. Kaplan–Meier Plots of Mortality

By the end of the study, 354 men (48.4%) had died from any cause (Panel A). Death attributed to prostate cancer or treatment occurred in 52 men (7.1%) (Panel B). Data from the radical-prostatectomy group are shown in red, and data from the observation group in blue.

Figure 3. Forest Plots for Primary and Secondary Outcomes

There were no significant between-group differences in all-cause mortality according to age, score on the Gleason histologic scale (<7 vs. ≥7 on a scale of 2 to 10, with 10 indicating the most poorly differentiated tumors), self-reported race, self-reported performance status (0 [fully active] vs. 1 to 4, with higher scores indicating poorer functional status), or score on the Charlson co-morbidity index (Panel A), but there was a significant interaction between study group and baseline PSA value (P = 0.04 for interaction) and a borderline interaction (P = 0.07) for tumor risk (D’Amico tumor risk score [low, intermediate, or high], which was based on tumor stage, histologic score, and PSA level). Prostate-cancer mortality did not differ significantly between the study groups according to age, race, score on the Charlson comorbidity index, or self-reported performance status (Panel B), although there was borderline evidence of an interaction for PSA value and tumor-risk category (P = 0.11 for interaction for both comparisons). The bars indicate 95% confidence intervals, and the size of the symbol indicates the weight of the estimate.