Ning Ning1, Ting Zhan2, Yujuan Zhang2, Qian Chen2, Fengzhi Feng3, Zhuo Yang2, Zhongjuan Liu2, Danfei Xu2, Fei Wang2, Ye Guo2, Jia Xing2, Yuanyuan Guan3, Wei Cui4. 1. Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China; Department of Obstetrics and Gynecology, The First Affiliated Hospital of Harbin University, Harbin, China. 2. Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. 3. Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. 4. Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. Electronic address: wendycuiwei@hotmail.com.
Abstract
BACKGROUND: Conventional cytokeratin (CK)-based methods to detect circulating tumor cells (CTCs) often present suboptimal sensitivities for decreased or non-expression of cytokeratin in some CTCs. We clinically investigated a new method that combines immunocytochemistry staining (ICC) of CD45 and fluorescence in situ hybridization (FISH). METHODS: Circulating epithelial cells from 141 subjects were enriched using an EpCAM-independent strategy and then identified by either a combination of FISH with chromosome 8 centromere probe (CEP8) and ICC staining of CD45 (CD45-FISH) or ICC staining of CK. RESULTS: For detecting CTCs enriched from lung cancers, CD45-FISH had larger areas under ROC curves of 0.963 (P=0.000) compared to ICC (0.653; P=0.031) using cut-off values of 2 and 1 cell/3.75ml blood with sensitivities of 83.3% and 43.3%, specificities of 98.6% and 89.5%, respectively. Moreover, CD45-FISH showed 76.2% sensitivity in detecting CTCs in ovarian cancers (P<0.001). Four of six ovarian cancers showed dramatical decrease in both CTCs and serum CA125 on the 7th day after surgery. CONCLUSION: CD45-FISH method had improved sensitivity and specificity in detecting CTCs of lung and ovarian cancers compared to ICC-CK. This combined detection strategy may be useful in detecting or monitoring CTCs after ovarian cancer surgery.
BACKGROUND: Conventional cytokeratin (CK)-based methods to detect circulating tumor cells (CTCs) often present suboptimal sensitivities for decreased or non-expression of cytokeratin in some CTCs. We clinically investigated a new method that combines immunocytochemistry staining (ICC) of CD45 and fluorescence in situ hybridization (FISH). METHODS: Circulating epithelial cells from 141 subjects were enriched using an EpCAM-independent strategy and then identified by either a combination of FISH with chromosome 8 centromere probe (CEP8) and ICC staining of CD45 (CD45-FISH) or ICC staining of CK. RESULTS: For detecting CTCs enriched from lung cancers, CD45-FISH had larger areas under ROC curves of 0.963 (P=0.000) compared to ICC (0.653; P=0.031) using cut-off values of 2 and 1 cell/3.75ml blood with sensitivities of 83.3% and 43.3%, specificities of 98.6% and 89.5%, respectively. Moreover, CD45-FISH showed 76.2% sensitivity in detecting CTCs in ovarian cancers (P<0.001). Four of six ovarian cancers showed dramatical decrease in both CTCs and serum CA125 on the 7th day after surgery. CONCLUSION: CD45-FISH method had improved sensitivity and specificity in detecting CTCs of lung and ovarian cancers compared to ICC-CK. This combined detection strategy may be useful in detecting or monitoring CTCs after ovarian cancer surgery.