Authors' Affiliations: 1Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute; 2Department of Epidemiology, Nagoya University Graduate School of Medicine, Nagoya, Japan; 3Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan; and 4Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Kyoto, Japan (2010-06-01時点)