1. The 1st Department of Internal Medicine, Wakayama Medical University, Wakayama 641-8509, Japan
2. Department of Diagnostic Pathology and Cytology, Kuma Hospital, Kobe 650-0011, Japan
3. Department of Surgery, Kanagawa Cancer Center, Yokohama 241-8515, Japan
4. Department of Otorhinolaryngology, KKR Sapporo Medical Center, Sapporo 062-0931, Japan