Tumor cell-based liquid biopsy using high-throughput microfluidic enrichment of entire leukapheresis product

Circulating Tumor Cells (CTCs) encompass multiple analytes, interrogated by sampling blood from patients with cancer. However, the clinical utility of tumor cell-based liquid biopsy has proven to be limited since CTCs are rare, and current technologies cannot process larger blood volumes required to isolate a sufficient number of tumor cells. We have described a high-throughput microfluidic prototype utilizing high-flow channels and amplification of cell sorting forces through magnetic lenses. Here, we apply this technology to analyze patient-derived leukapheresis products, interrogating a mean blood volume of 5.83 liters from patients with metastatic cancer and achieving a median of 2,799 CTCs per patient. Isolation of many CTCs from individual patients enables characterization of their morphological and molecular heterogeneity, including cell and nuclear size and RNA expression. It also allows robust detection of gene copy number variation (CNV), a definitive cancer marker with potential diagnostic applications. High-volume microfluidic enrichment of CTCs constitutes a new dimension in liquid biopsies.