Department of Hematology, Oncology, and Respiratory Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Okayama, Japan. Center of Innovative Clinical Medicine, Okayama University Hospital, Okayama, Okayama, Japan. Division of Cancer Epidemiology and Prevention, Department of Preventive Medicine, Aichi Cancer Center Research Institute, Nagoya, Aichi, Japan. Department of Respiratory Medicine, Yamaguchi Ube Medical Center, Ube, Yamaguchi, Japan. Department of Respiratory Medicine, Kure Kyosai Hospital, Kure, Hiroshima, Japan. Health Service Center, Okayama University, Okayama, Okayama, Japan. Center for Clinical Oncology, Okayama University Hospital, Okayama, Okayama, Japan. Department of Allergy and Respiratory Medicine, Okayama University Hospital, Okayama, Okayama, Japan. Department of Respiratory Medicine, Okayama Medical Center, Okayama, Okayama, Japan.