Background: Prostate cancer is the most common noncutaneous malignancy and the second leading cause of cancer death in men. Ninety percent of men with prostate cancer are over aged 60 years, diagnosed by early detection with the prostate specific antigen (PSA) blood test and have disease believed confined to the prostate gland (clinically localized). Common treatments for clinically localized prostate cancer include watchful waiting surgery to remove the prostate gland (radical prostatectomy), external beam radiation therapy and interstitial radiation therapy (brachytherapy) and androgen deprivation. Little is known about the relative effectiveness and harms of treatments due to the paucity of randomized controlled trials. The VA/NCI/AHRQ Cooperative Studies Program Study #407: Prostate cancer Intervention Versus Observation Trial (PIVOT), initiated in 1994, is a multicenter randomized controlled trial comparing radical prostatectomy to watchful waiting in men with clinically localized prostate cancer.
Methods: We describe the study rationale, design, recruitment methods and baseline characteristics of PIVOT enrollees. We provide comparisons with eligible men declining enrollment and men participating in another recently reported randomized trial of radical prostatectomy versus watchful waiting conducted in Scandinavia.
Results: We screened 13,022 men with prostate cancer at 52 United States medical centers for potential enrollment. From these, 5023 met initial age, comorbidity and disease eligibility criteria and a total of 731 men agreed to participate and were randomized. The mean age of enrollees was 67 years. Nearly one-third were African-American. Approximately 85% reported they were fully active. The median prostate specific antigen (PSA) was 7.8 ng/mL (mean 10.2 ng/mL). In three-fourths of men the primary reason for biopsy leading to a diagnosis of prostate cancer was a PSA elevation or rise. Using previously developed tumor risk categorizations incorporating PSA levels, Gleason histologic grade and tumor stage, approximately 43% had low risk, 36% had medium risk and 20% had high-risk prostate cancer. Comparison to our national sample of eligible men declining PIVOT participation as well as to men enrolled in the Scandinavian trial indicated that PIVOT enrollees are representative of men being diagnosed and treated in the U.S. and quite different from men in the Scandinavian trial.
Conclusions: PIVOT enrolled an ethnically diverse population representative of men diagnosed with prostate cancer in the United States. Results will yield important information regarding the relative effectiveness and harms of surgery compared to watchful waiting for men with predominately PSA detected clinically localized prostate cancer.