1. Department of Oncology, The Second People's Hospital of Neijiang City, Neijiang, Sichuan 641000, P.R. China
2. Department of Oncology, The First People's Hospital of Neijiang City, Neijiang, Sichuan 641000, P.R. China
3. Department of General Medicine, The People's Hospital of Luzhou City, Luzhou, Sichuan 646000, P.R. China
4. Department of Cardiothoracic Surgery, Sun Yat Sen Memorial Hospital, Sun Yat Sen University, Guangzhou, Guangdong 510080, P.R. China
5. Shenzhen University Medical School, Shenzhen University, Shenzhen, Guangdong 518060, P.R. China