Single-Cell Transcriptomics Reveals Novel Cell States in Human Failing Hearts

Background: Peritoneal metastases originating from colorectal cancer (CRC) represent a particularly aggressive and therapeutically challenging manifestation of the disease, often associated with significantly reduced overall survival and poor response to conventional systemic chemotherapy. Unlike liver or lung metastases, peritoneal dissemination is frequently underdiagnosed or detected at an advanced stage due to the limitations of current imaging techniques, such as CT and MRI, which exhibit low sensitivity for small-volume disease or early peritoneal involvement. Methods and Results: This review systematically examines the latest research and clinical findings on the application of liquid biopsy techniques to colorectal peritoneal metastasis. Key biomarker types investigated include circulating tumor DNA (ctDNA), microRNAs, exosomes, tumor-educated platelets, and methylation signatures. These biomarkers demonstrate varying degrees of sensitivity and specificity for detecting peritoneal involvement, with ctDNA and microRNAs showing particular promise in early studies. Exosomes, small extracellular vesicles carrying molecular cargo, offer insights into cell–cell communication and may help delineate tumor biology and response to therapy. Despite encouraging data, several challenges limit routine clinical implementation. These include low tumor shedding in peritoneal disease, spatial heterogeneity, and technical limitations in detection sensitivity. Additionally, a lack of standardized protocols for sample processing and analysis hinders reproducibility and cross-study comparisons. Conclusion: Liquid biopsy holds significant potential for transforming the diagnostic and prognostic landscape of colorectal peritoneal metastases. By enabling frequent, real-time, and noninvasive assessment of disease burden and therapeutic efficacy, these technologies may complement or even outperform traditional imaging in selected contexts. Further research is needed to validate biomarker panels, standardize methodologies, and define their role in personalized management strategies for this high-risk patient population.