Prostate cancer is the most common cancer found in American men and is the second most common cause of cancer-related death in males.1 Approximately 240,000 new cases of prostate cancer will be diagnosed in 2012.1 Fortunately with the advent of widespread Prostate Specific Antigen (PSA) screening, the death rate from prostate cancer has been steadily decreasing, but the incidence of low-risk, clinically localized cancer has been on the rise.1 Treatment options for this tumor grade include radical prostatectomy, radiation, or observation. Numerous studies have been conducted to determine whether exposing patients to the possible adverse effects of surgery or radiation rather than observation provides any benefit towards decreasing mortality in this population. The results have been inconclusive.
The Prostate Cancer Intervention versus Observation Trial (PIVOT) study group recently investigated whether radical prostatectomy versus observation for localized prostate cancer reduced all-cause mortality and prostate-cancer mortality. In order to be eligible for the study, men had to have a prostate cancer diagnosed as T1-T2NxM0 within the last 12 months, a PSA value less than 50 ng/mL, age 75 years or younger, negative for bone metastases, and a life expectancy of at least 10 years from the time of randomization. Enrollment began in November 1994 and ended in January 2002, gathering 5,023 men eligible to participate in the study of which only 731 (14.6%) agreed to undergo randomization to either radical prostatectomy (n = 364) or observation (n = 367). The primary and secondary outcomes examined were all-cause mortality and prostate-cancer mortality, respectively.2
The baseline characteristics between the two treatment groups did not differ significantly. The mean age was 67 years with a median PSA value of 7.8 ng/mL. Forty percent of the men had low-risk cancer (Gleason score ≤ 6, PSA ≤ 10, and Tumor Stage T1a, T1b, T1c or T2a); 34% had intermediate-risk cancer (PSA 10.1 – 20 ng/mL or Gleason score = 7 or Stage T2b); and 21% had high-risk cancer (PSA > 20 ng/mL or Gleason score 8-10 or Stage T2c). Of the 364 men assigned to the radical prostatectomy group, only 287 (78.8%) underwent an attempted radical prostatectomy while 311 (85.4%) received definitive therapy (radical prostatectomy, attempted radical prostatectomy, underwent external beam radiotherapy, underwent brachytherapy, or underwent unspecified irradiation). Among men assigned to the observation group, 37 (10.1%) underwent an attempted radical prostatectomy while 75 (20.4%) received definitive therapy. The median follow-up from randomization until death or the end of the study was 10.0 years.2
At the end of the study, the investigators found that 171 (47.0%) of the men in the radical prostatectomy group had died compared with 183 (49.9%) in the observation group, but this was not statistically significant (hazard ratio, 0.88; 95% CI, 0.71 to 1.08; P=0.22; absolute risk reduction, 2.9 percentage points; 95% CI, -4.1 to 10.3). The median survival time was 13.0 years (95% CI, 12.2 to 13.7) in the radical prostatectomy group and 12.4 years (95% CI, 11.4 to 13.1) ...