Microwell Cell-Chip-Based Selective Culture Platform Enables Accurate Capture of Viable Breast Cancer Circulating Tumor Cells

Circulating tumor cells (CTCs), known as the "seeds" of metastasis, serve as dynamic liquid biopsy biomarkers for cancer diagnosis, therapeutic monitoring, prognostic evaluation, and metastasis research. However, their extreme rarity in blood makes detection technically demanding, limiting their clinical application. Most methods prioritize capture yield but compromise CTC viability and cluster integrity, hindering deep analysis and studies. To overcome these limitations, we developed a microwell cell-chip-based selective culture platform (MCSCP), capable of accurately capturing viable and morphologically diverse CTCs from 1 mL blood using one MWC-chip, achieving a recovery rate of up to ~91%. This platform creates low-adherent and nutrient-deprived culture conditions on the MWC-chip, selectively allowing stress-tolerant CTCs to survive and preserve their cluster structure, without cell damage and batch enrichment. This improves enumeration accuracy and supports in-depth analysis. In a cohort of 200 breast cancer patients, the platform detected CTCs in over 97% of cases, with a median count of 12 CTCs/mL. Notably, 67.7% of patients carried CTC clusters, which proved to be more predictive of metastasis and recurrence than total CTC counts. Beyond accurate CTC enumeration for dynamic therapeutic monitoring, the platform also enables single-cell multi-omics analyses, providing a promising tool for precision oncology and metastasis research.