1. Department of Oncology, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, P.R. China
2. Department of Thoracic Surgery, The Center Hospital of Xi’an, Shaanxi, P.R. China
3. Department of Oncology, Shaanxi Provincial Tumor Hospital, Xi’an, Shaanxi, P.R. China
4. Department of General Surgery, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, P.R. China