Clinical significance of detecting circulating tumor cells in colorectal cancer using subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH)

// Wei Wu 1, * , Zhenzhen Zhang 2, * , Xian Hua Gao 3, * , Zhen Shen 1 , Yan Jing 1 , Haibo Lu 1 , Heng Li 1 , Xiaoye Yang 1 , Xiangbin Cui 1 , Yuqing Li 1 , Zheng Lou 3 , Peng Liu 3 , Cun Zhang 1 , Wei Zhang 3 1 Department of General Surgery, The Aviation Hanzhong 3201 Hospital, Xi’an Jiao Tong University, Hanzhong 723000, Shaanxi, China 2 Zhangjiang Center for Translational Medicine, Shanghai 200120, China 3 Department of Colorectal Surgery, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China * These authors have contributed equally to this work Correspondence to: Wei Zhang, email: weizhang2000cn@163.com Cun Zhang, email: zhangcun3201@sina.com Keywords: colorectal cancer, circulating tumor cells, biomarker, recurrence, FISH Received: October 04, 2016 Accepted: January 27, 2017 Published: February 17, 2017 ABSTRACT Circulating tumor cells (CTC) are useful in early detection of colorectal cancer. This study described a newly developed platform, integrated subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH), to assess CTCs in colorectal cancer. CTCs were detected by SE-iFISH in 40 of 44 preoperative colorectal cancer patients, and yielded a sensitivity of 90.9%, which was significantly higher than CellSearch system (90.9% vs. 43.2%, P=0.033). No significant association was found between tumor stage, survival and preoperative CTC number. CTCs were detected in 10 colorectal cancer patients one week after surgery; seven patients with decreased CTC numbers (compared with preoperative CTC number) were free of recurrence; whereas two of the three patients with increased CTC numbers had tumor recurrence. Moreover, CTCs were detected in 34 colorectal cancer patients three months after surgery; patients with CTC<2 at three months after surgery had significantly longer Progression Free Survival than those with CTC>=2 (P=0.019); patients with decreased CTC number (compared with preoperative CTC number) had significantly longer Progression Free Survival than those with increased CTC number (P=0.003). In conclusion, CTCs could be detected in various stages of colorectal cancer using SE-iFISH. Dynamic monitoring of CTC numbers could predict recurrence and prognosis.