化疗联合手术治疗已逐渐成为结直肠癌肝转移病人的标准治疗方式。对于可切除的大肠癌肝转移病人是否需要术前化疗仍存在争议。存在预后不良因素时应接受术前化疗，术前化疗不应＞6周期。不可切除的肝转移病人均应接受术前化疗，术前化疗后定期复查，如转化为可切除，应立即切除。一般认为，停用化疗4周后可以手术切除肝转移灶，但如果联合贝伐单抗，应在停止治疗6~8周后进行手术。

The best timing of preoperative chemotherapy for liver metastases of colorectal cancer        XING Bao-cai, WANG Hong-wei. Department of Hepato-bilio-pancreatic Surgery I, Peking University School of Oncology，Beijing Cancer Hospital，Beijing 100142, China
Corresponding author：XING Bao-cai, E-mail：xingbaocai88@sina.com
Abstract    The combination of surgery and chemotherapy has become the standard treatment for patients with liver metastases of colorectal cancer. There is controversy that preoperative chemotherapy should be considered in patients with resectable liver metastases of colorectal cancer. The patients with prognostic factor of poor survival should be received preoperative chemotherapy. Surgery should be performed after a maximum of 6 cycles of preoperative chemotherapy. In patients with unresectable liver metastases, there is no question regarding the indication of chemotherapy. They should be carefully monitored and performed surgery as soon as the metastases become resectable. Surgery can be performed after 4 weeks from the last cycle of chemotherapy, and 6-8 weeks following chemotherapy plus bevacizumab.