1. School of Medicine, Oregon Health and Science University, Portland, Oregon, USA.
2. Department of Urology, University of Wisconsin, Wisconsin, USA.
3. Department of Urology, West Virginia University, Wheeling, West Virginia, USA.
4. Department of Urology, Oregon Health and Science University, Portland, Oregon, USA.
5. Biostatistics Shared Resources, Knight Cancer Institute, Portland, Oregon, USA.
6. Department of Pediatric Urology, Doernbecher Children's Hospital, Oregon Health and Science University, Portland, Oregon, USA.