1. Cancer Research Center, School of Medicine, Xiamen University, Xiamen, Fujian, PR China
2. Xiamen University Research Center of Retroperitoneal Tumor Committee of Oncology Society of Chinese Medical Association, Xiamen University, Xiamen, Fujian, PR China
3. Department of Biostatistics, School of Public Health, Harvard University, Cambridge, MA.
4. Department of Hepatobiliary Surgery, Xiang’an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, PR China