1. Department of General Surgery, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, P.R. China
2. Department of General Surgery, The Third People's Hospital of Dalian, Dalian Medical University, Dalian, Liaoning 116033, P.R. China
3. Department of Pathology, The Third People's Hospital of Dalian, Dalian Medical University, Dalian, Liaoning 116033, P.R. China