CTC Isolation and Molecular Profiling

CTC enrichment and enumeration were performed using the CellSearch^® System and the CellSearch^® Epithelial Cell Kit, and single cells, small pools of CTCs (range 8–23 cells per pool) and white blood cells (WBC) were recovered from the same CellSearch^® cassettes as the single cells (Supplementary Table 1) using the DEPArray™ system (all Menarini Silicon Biosystems, Bologna, Italy) according to the manufacturer’s protocols, as described previously [13 (link)]. Single cells and pools of cells were amplified using the Ampli1™ WGA kit, and the presence of amplified DNA was assessed by using the Ampli1™ QC Kit (Menarini Silicon Biosystems) and assessed by multiplex PCR as described previously [13 (link)]. Only samples with a genomic integrity index (GII) ≥ 2 were analysed.