David F. Paulson, MD

The Prostate Cancer Intervention Versus Observation Trial (PIVOT) should prove interesting in that the study design will permit observation of the natural history of a potentially lethal malignant disease, influenced only by palliative treatments. My comments will focus on the concerns raised by this study design. I will not address possible biases of the trial introduced by: (1) enrollment of less than 20% of the eligible population; (2) an enrollment rate per participating center of less than 3 patients per year; (3) a 7-year enrollment period; and (4) a 12-year follow-up (for a total trial duration of 19 years).