Advancements and Applications of Liquid Biopsies in Oncology: A Narrative Review

Abstract

According to the World Health Organization (WHO), nearly 10 million people died from cancer worldwide in 2020, making it the leading cause of mortality. Liquid biopsies, which provide non-invasive and real-time monitoring of tumor dynamics, have evolved into innovative diagnostic techniques in the field of oncology. Liquid biopsies offer important insights into tumor heterogeneity, treatment response, minimum residual disease identification, and personalized treatment of cancer through the analysis of circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), extracellular vesicles, and microRNAs. They offer several advantages over traditional tissue biopsies, such as being less invasive, more convenient, more representative of tumor heterogeneity and dynamics, and more informative for guiding personalized treatment decisions. Liquid biopsies are being utilized increasingly in clinical oncology, particularly for patients with metastatic disease who require ongoing monitoring and treatment modification. In this narrative review article, we review the latest developments of liquid biopsy technologies, their applications and limitations, and their potential to transform diagnosis, prognosis, and management of cancer patients.

Clinical impact of epithelial–mesenchymal transition for cancer therapy

“…In therapeutics, the emphasis is on targeting the molecular pathways that drive EMT. 323 This could involve the development of drugs that inhibit key signalling molecules or pathways implicated in EMT, such as TGF-β, Wnt and Hedgehog. 324 Another promising approach is the use of epigenetic therapies that can reverse the epigenetic modifications driving the EMT process.…”

“…The use of advanced imaging techniques and liquid biopsies to detect these markers in real‐time could provide critical insights into tumour progression and metastatic potential, enabling personalised treatment strategies. In therapeutics, the emphasis is on targeting the molecular pathways that drive EMT 323 . This could involve the development of drugs that inhibit key signalling molecules or pathways implicated in EMT, such as TGF‐β, Wnt and Hedgehog 324 .…”

Exploring the Immunological Profile in Breast Cancer: Recent Advances in Diagnosis and Prognosis through Circulating Tumor Cells

“…Reportedly, micrometastases and macrometastasis are formed by around 2.5% and 0.01% of CTCs, respectively [4]. The utilization of multiple sampling in detecting CTCs offers a real-time "liquid biopsy", significantly aiding in treatment selection and optimization [26]. The CellSearch system for detecting CTCs has obtained approval from the Food and Drug Administration (FDA) for monitoring the progression of metastatic BC therapeutically [27].…”

Circulating Cancer-Associated Macrophage-like Cells as a Blood-Based Biomarker of Response to Immune Checkpoint Inhibitors

“…Although several blood-based biomarkers have been investigated in the last few decades, the prediction of ICI response still currently relies on PD-L1 tumor expression, facing the major criticism inherent to tumor biopsy specimen analysis. In the last decade, an increasing number of studies allowed liquid biopsy to be introduced as a noninvasive approach in precision oncology to better address spatial and temporal cancer heterogeneity through longitudinal monitoring of tumors at different time points, helping inform clinical decision making [5][6][7]. Circulating tumor cells (CTCs), as a 'liquid biopsy' from blood, provide important prognostic and predictive information in cancer management [8].…”