目的：探讨流式细胞仪检测结直肠癌根治术前后循环肿瘤细胞（circulating tumor cell，CTC）和循环肿瘤干细胞（circulating tumor stem cell，CTSC）作为患者临床预测指标的可行性和临床价值。方法：入组首诊初治50例结直肠癌患者，手术前后各抽取15 ml外周血。分离单个核细胞后分成两份，一份标记CTC标志物（CD45、EpCAM 和CK），另一份标记CTSC标志物（CD45、EpCAM、CD44和CD133），Moflo XDP流式细胞仪对其进行检测， CD45-EpCAM+ CK+细胞确定为CTC；CTSC确定为3群：CD44+CTSC、 CD133+ CTSC和CD44+ CD133+ CTSC。 结果：结直肠癌根治术前患者CTC和CD44+CTSC阳性率分别为34%和44% ，CD133+ CTSC和CD44+ CD133+ CTSC是 24%和0；术后患者CTC和CD44+CTSC阳性率分别为38%和 54%，CD133+ CTSC 和CD44+ CD133+ CTSC分别为26%和0。根治术前后CTC阳性率都与肿瘤T分期有关联(P<0.05)；术后CTC与肿瘤的浸润深度、淋巴结转移和远处转移有关联(P<0.05)；术前CD44+CTSC与肿瘤的浸润深度有关联。结论：根治术前后CTC及术前 CD44+CTSC阳性率都具有临床预测指标的可行性和价值，术后CTC阳性率可能是更好的预测指标。

Objective:To explore the feasibility and clinical value of indentifying circulating tumor cells (CTCs) and circulating tumor stem cells (CTSCs) by Flow cytometry before and after the radical resection of colorectal carcinoma for the prognosis prediction of colorectal cancerl (CRC) patients. Methods: Altogether 50 colorectal cancer patients without previous chemotherapeutic treatment were recruited. Approximately 15 ml peripheral blood was drawn from each patient before and one week after surgery. Mononuclear cells were isolated and divided into two groups: one was tagged with CTC surface markers (CD45, EpCAM and CK), and the other with CTSC markers (CD45, EpCAM, CD44 and CD133). After examination by Moflo XDP flow cytometry, CTC was difined as CD45-EpCAM+ CK+; and CTSC was categorized into three groups: CD44+CTSC(CD45-EpCAM+CD44+), CD133+ CTSC (CD45-EpCAM+CD133+ ) ,CD44+ CD133+ CTSC (CD45-EpCAM+CD44+CD133+ ). Results: Positive rates of pre-operative CTC and CD44+CTSC were 34% and 44%, respectively, while the positive rates of CD133+ CTSC and CD44+ CD133+ CTSC were 24% and 0%, respectively. Positive rates of post-operative CTC and CD44+CTSC were 38% and 54%, respectively, while the positive rates of CD133+ CTSC and CD44+ CD133+ CTSC were 26% and 0%, respectively. Both pre- and post-operative CTC levels were associated with the T stages of tumor (P<0.05); Moreover, post-operative CTC level had significant correlation with infiltration depth, lymphnode metastasis and distant metastasis (P<0.05). Pre-operative CD44+CTSC level was associated with tumor infiltration depth (P<0.05). Conclusion: Pre- and post-operative CTCs and preoperative CD44+CTSC all have the feasibility and practical value to be the prognostic biomarkers; Postoperative CTC positive rate may serve as a better predictive biomarker for colorectal cancer.

福建省医学创新基金资助项目（No.2015-CXB-4）；福建省自然科学基金资助项目（No.2016J01436）；福建省卫教联合项目(No. WKJ-FJ-14)；国家临床重点专科建设基金资助项目(No.2013-544)