肿瘤的复发和转移是患者死亡的主要原因。血行播散是肿瘤转移的重要途径,肿瘤细胞进入血液循环是发生远处转移的关键步骤之一。外周血循环肿瘤细胞(circulating tumor cells,CTCs)是指自发或因诊疗操作进入外周血循环的肿瘤细胞。研究发现,肿瘤细胞脱离原发灶,侵袭外周组织,并进入血液循环是实现肿瘤转移的最初阶段,其为最终形成转移灶提供了可能。监测患者CTCs数量的变化可能比传 Tumor recurrence and metastasis is the main cause of death in patients. Hematogenous spread is an important way of tumor metastasis, tumor cells into the blood circulation is one of the key steps in the distant metastasis. Circulating circulating tumor cells (circulating tumor cells, CTCs) refers to spontaneous or due to medical treatment into the peripheral blood circulation of tumor cells. The study found that tumor cells detached from the primary tumor, invasion of peripheral tissues, and into the blood circulation is the initial stage of tumor metastasis, which provides the possibility of the final formation of metastases. Monitoring the number of patients with CTCs may be more than pass