1. Department of Medical Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei, China
2. Department of Gastrointestinal Surgery, the First Affiliated Hospital of Anhui Medical University, Hefei, China
3. German Cancer Research Center (DKFZ), Heidelberg, Germany
4. Department of Tumor Cytology, the First Affiliated Hospital of Anhui Medical University, Hefei, China