Circulating Tumor Cell Detection for Therapeutic and Prognostic Roles in Breast Cancer

Circulating tumor cells (CTCs) are pivotal liquid biopsy (LB) biomarkers for breast cancer (BC), offering non-invasive insights into tumor progression and metastasis. Despite their clinical promise, CTC detection remains technically challenging due to their extreme rarity in peripheral blood.

This review systematically evaluates CTC detection methodologies, including immunoaffinity-based approaches and biophysical techniques, which exhibit inherent trade-offs in sensitivity, specificity, and compatibility with downstream analyses. Furthermore, post-isolation molecular characterization methods spanning genomic, transcriptomic, and proteomic analyses are also critically assessed.

CTC molecular profiling holds significant clinical relevance, enabling early diagnosis, prognostic stratification, and real-time monitoring of therapeutic response. Baseline CTC counts or quantitative/phenotypic changes during treatment inform therapeutic decision-making, predict drug resistance, and correlate with recurrence risk and metastatic progression.

Multimodal analysis integrating CTC morphology, surface markers, and molecular alterations advances precision therapy. However, standardization of detection platforms and clinical validation of CTC-guided protocols remain essential.