1. Department of Urology, Faculty of Medicine, University of Toyama, Toyama Toyama, Japan
2. Department of Biostatistics, Sapporo Medical University, SapporoHokkaido, Japan
3. Department of Urology, Sapporo Medical University School of Medicine, Sapporo Hokkaido, Japan
4. Japan Clinical Oncology Group Data Center, National Cancer Center Hospital, Tokyo, Japan
5. Department of Urology, Kyoto University Graduate School of Medicine, Kyoto, Japan
6. Department of Urology, Nara Medical University, Kashihara, Nara, Japan
7. Department of Urology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan