1 Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, 510060, P. R. China.
2 Department of Colorectal Surgery, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, P. R. China.
3 Department of Gastrointestinal Medical Oncology, Peking University Cancer Hospital, Beijing, 100142, P. R. China.
4 Department of Medical Oncology, Tongji University Shanghai East Hospital, Shanghai, 200120, P. R. China.
5 Department of Surgical Oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310009, P. R. China.