CIRCULATING TUMOUR DNA IN AFRICA: A STRATEGIC ANALYSIS OF A MINIMALLY INVASIVE BIOMARKER FOR CANCER DETECTION AND MONITORING

Cancer diagnostic pathways in Africa face delays, uneven pathology access and limited molecular testing. Circulating tumour DNA (ctDNA) offers minimally invasive access to tumour-derived molecular information, but its value depends on the clinical question, assay performance and availability of subsequent care. This narrative review examines ctDNA biology, analytical platforms and clinical applications, then evaluates priorities for African implementation. Targeted literature checks for this revision covered clinical trials, professional recommendations, cancer surveillance sources, and African studies. Plasma genotyping has defined uses in advanced cancer, while negative results may require tissue testing. Molecular residual disease predicts recurrence, but evidence for treatment changes is tumour- and stage-specific. A methylation-based multi-cancer validation study reported 99.5% specificity but only 16.8% stage I sensitivity. Ghanaian breast-cancer research demonstrates genomic feasibility; a multicentre East African Burkitt lymphoma study provides stronger evidence of diagnostic accuracy and shorter turnaround time. Neither establishes effectiveness across all cancers or African health systems. Specimen handling, clonal haematopoiesis, assay costs, pathology access and access to appropriate treatment remain decisive constraints. Implementation should begin with defined indications, locally evaluated workflows and quality assurance. Prospective evaluation should measure clinical benefit, total pathway costs and equitable access before wider expansion.