Cross-Cancer Detectability of ctDNA Biomarkers in Asian Populations: Implications for Pan-Cancer Detection.

BACKGROUND: Cancer remains a leading cause of global mortality, making early detection essential for improvingpatient outcomes. Circulating tumor DNA (ctDNA) has emerged as a minimally invasive liquid biopsy approach for cancer detection and monitoring. Nevertheless, current ctDNA research is dominated by mutation-based analyses, which tend to be highly heterogeneous across cancer types and may therefore limit their usefulness for pan-cancer detection. OBJECTIVE: This review aimed to map ctDNA-detected gene biomarkers across cancer types in Asian populations and to identify genomic alteration patterns with potential relevance for pan-cancer detection. METHODS: Following the PRISMA 2020 guidelines, PubMed was systematically searched for studies investigating tumor-specific ctDNA in Asian cancer populations. Data were extracted at the gene-event level, treating each reported genomic alteration as an independent evidence entry. Genes, alteration types, and associated cancer types were synthesize using a descriptive frequency-based evidence mapping approach. Reported clinical relevance was also summarized to provide clinical context for the identified biomarkers. RESULTS: A total of 100 studies identified 113 ctDNA biomarkers across 23 cancer types, with lung, colorectal, and breast cancers being the most frequently investigated. Mutation events were the most commonly reported, reflecting the dominance of mutation-focused ctDNA assays. However, mutation profiles were highly heterogeneous and largely cancer-specific. In contrast, gene amplification events, particularly involving ERBB2, MET, and MYC, were reported across multiple cancer entities and demonstrated broader cross-cancer distribution, suggesting shared oncogenic mechanisms rather than lineage-specific events. CONCLUSION: This descriptive evidence mapping suggests that the potential relevance of ctDNA biomarkers in Asian populations may depend more on the type of genomic alteration than on gene-reporting frequency alone. Mutation-based ctDNA biomarkers were predominantly associated with tumor-specific applications, whereas amplification-based alterations were observed across multiple cancer types. These findings provide a framework for future biomarker prioritization for cancer detection and require validation through studies evaluating clinical performance and prospective implementation.