1. Tumor Etiology & Screening Department of Cancer Institute & General Surgery, the First Hospital of China Medical University, Shenyang, Liaoning 110001, PR China
2. Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, NO. 44 Xiaoheyan Road, Dadong District, Shenyang 110042, Liaoning Province, PR China
3. Key Laboratory of Cancer Etiology & Prevention in Liaoning Education Department, the First Hospital of China Medical University, Shenyang, Liaoning 110001, PR China
4. Key Laboratory of GI Cancer Etiology & Prevention in Liaoning Province, the First Hospital of China Medical University, Shenyang, Liaoning 110001, PR China