Liquid Biopsies in the Early Diagnosis, Prognosis, and Tailored Treatment of Colorectal Cancer

Introduction: Liquid biopsies provide a less-invasive option to tissue biopsies for the early diagnosis, prognosis, and tailored therapy of colorectal cancer (CRC). CRC is a major cause of cancer-related death, and early identification is essential for improving patient outcomes. Review: Conventional diagnostic techniques, including colonoscopy and tissue biopsy, may be enhanced by liquid biopsies that examine circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), extracellular vesicles (EVs), and other indicators present in body fluids. These markers provide significant insights into tumor biology, heterogeneity, and therapeutic response. CTCs detected in early-stage CRC have prognostic significance for disease recurrence and survival, while ctDNA investigation may uncover genetic mutations, epigenetic alterations, and tumor development. The identification of ctDNA in minimal residual disease (MRD) postsurgery correlates with an elevated risk of recurrence and unfavorable prognosis, underscoring its use in assessing treatment effectiveness. Furthermore, non-coding RNAs (ncRNAs) contained inside EVs provide potential prospective biomarkers and therapeutic targets, facilitating diagnosis and treatment assessment. Notwithstanding the potential of liquid biopsies, obstacles persist in assay standardization, sensitivity enhancement, and the management of tumor heterogeneity. Additional extensive research is required to determine their function in clinical practice. Conclusion: Overall, liquid biopsies serve as a potential instrument for real-time monitoring, evaluating therapy responses, and directing individualized therapeutic strategies in CRC patients.