1. Clinical Research Center Shanghai Jiao Tong University School of Medicine Shanghai China
2. KLATASDS‐MOE, School of Statistics East China Normal University Shanghai China
3. Department of Biometrics Servier Pharmaceuticals Boston Massachusetts USA
4. Department of Gastrointestinal Medical Oncology The University of Texas MD Anderson Cancer Center Houston Texas USA
5. Department of Biostatistics The University of Texas MD Anderson Cancer Center Houston Texas USA