1. Department of Pathology, Sapporo Medical University School of Medicine, Chuo-Ku, Sapporo 060-8556, Japan
2. Department of Urology, Sapporo Medical University School of Medicine, Chuo-Ku, Sapporo 060-8556, Japan
3. Department of Urology, Graduate School of Medicine and Pharmaceutical Science for Research, University of Toyama, Toyama-Shi 930-0194, Japan