1. Department of Urology, University of Texas M. D. Anderson Cancer Center, Houston, Texas
2. Department of Genitourinary Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas
3. Department of Biostatistics, University of Texas M. D. Anderson Cancer Center, Houston, Texas
4. Division of Urology, Department of Surgery, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan
5. Department of Pathology, University of Texas M. D. Anderson Cancer Center, Houston, Texas