1. Department of Epidemiology and Health Statistics, Fujian Provincial Key Laboratory of Environment Factors and Cancer, School of Public Health, Fujian Medical University, Fuzhou, Fujian 350108, P.R. China
2. Department of Radiation Oncology, Affiliated Zhangzhou Hospital of Fujian Medical University, Zhangzhou, Fujian 363000, P.R. China
3. Department of Thoracic Surgery, Fujian Provincial Cancer Hospital, Fuzhou, Fujian 350014, P.R. China