Fig. 7: CTC isolation and diagnosis performance in clinical applications.

a The capture efficiency of different breast cell lines indicated that the CTC affinity interfaces could selectively capture several subtypes of breast cancer cells but not normal breast mammary epithelial cells (n = 3 samples, mean ± s.d.). b Distinct difference in the enumeration of CTCs in 1 mL blood samples from healthy volunteers (n = 10), benign patients (n = 34), non-metastatic breast cancer (BC) patients (n = 32), and metastatic BC patients (n = 24). Unpaired two-sided Student’s t test. The central dot is the median; box bounds are 25th and 75th percentiles, upper and lower limits of whiskers are 1.5 × interquartile ranges. Values outside of the upper and lower limits are defined as outliers. *p  <  0.05, **p  <  0.01, ***p  <  0.001, ****p  <  0.0001. c ROC analysis of CTC numbers between the cancer patient groups and healthy/benign groups. The receiver operating characteristic (ROC) curve showed good diagnostic performance (AUC = 0.991) in differentiating cancer patient groups and healthy/benign groups. d Immunofluorescence staining (DAPI/ER/HER2/CD45) of CTCs isolated from patients. Scale bar: 10 μm. CD45 was the biomarker for WBC and CK was the biomarker for CTC, with DAPI⁺/CK⁺/CD45^- cells recognized as CTCs and DAPI⁺/CK^-/CD45⁺ cells identified as WBCs. ER and HER2 were used for the profiling of three subtypes of BC CTCs, including luminal (HER2^{+ or -}/ER⁺), HER2-positive (HER2⁺/ER^-) and triple negative breast cancer (TNBC, belongs to basal-like subtype) (HER2^-/ER^-). 51 out of 56 molecular profiling results were in accordance with clinical diagnostic results. e Confusion matrix showing the subtyping accuracy of luminal, HER2, and TNBC by molecular profiling of CTCs. f Comparison of the CTC numbers isolated by A-f-M13-MB and CellSearch® or SE iFISH® in blood revealed a higher CTC capture ability and a better isolation performance of A-f-M13-MB in clinical applications. CellSearch® and SE iFISH® collected CTC from 7.5 mL and 6.0 mL blood, respectively, whereas our approach isolated CTC from 1.0 mL blood. A-f-M13-MB: Ni-IDA-MBs anchored with aptamer-modified-flexible M13; Source data are provided as a Source Data file.