Background: Liquid biopsy is a minimally invasive diagnostic method that analyses circulating tumor-derived analytes, such as circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), exosomes, and extracellular vesicles (EVs), to provide real-time information about tumour biology. It has become a key tool for early detection, prognosis, treatment monitoring, and assessment of minimal residual disease (MRD) in oncology.

Objective: To havea comprehensive overview of liquid biopsy technologies, their clinical applications, global adoption patterns, insights from Sub-Saharan Africa (SSA), and recent advancements, while highlighting implementation challenges and future directions.

Methods: A narrative review was conducted using literature from PubMed, Scopus, and Web of Science (2015–2025), focusing on global, Sub-Saharan African, and Nigerian studies. The research was evaluated for its relevance to technical innovations, biomarker utility, epidemiological data, and clinical integration.

Results: Liquid biopsy demonstrates enhanced sensitivity and specificity for cancer detection, with next-generation sequencing (NGS) and digital PCR enabling precise mutation characterisation. Circulating tumour DNA (ctDNA) is the most thoroughly studied biomarker, while circulating tumour cells (CTCs) and extracellular vesicles (EVs) provide further insights into cancer heterogeneity. Adoption is high in rich countries, while Sub-Saharan Africa has problems like poor infrastructure, highcosts, and a lack of technical skills. New systems that combine multi-omics, AI-driven analytics, and point-of-care devices are going to make clinical value better.

Conclusion: Liquid biopsy represents a revolutionary progression in oncology diagnostics, offering non-invasive, real-time molecular characterisation. To achieve fair global adoption, it is necessary to reduce economic, infrastructure, and legal barriers, especially in areas with limited resources.