Circulating Tumor DNA and Blood-Based Biomarkers for Predicting Cardiotoxicity in Cancer Therapy: Toward Precision Cardio-Oncology

Advances in cancer therapeutics have substantially improved survival across multiple malignancies but have concurrently increased the burden of cancer therapy-related cardiovascular toxicity, establishing cardio-oncology as an essential discipline situated at the interface of oncology and cardiovascular medicine. Despite growing incorporation of cardiac imaging and circulating cardiac biomarkers into surveillance strategies, current approaches remain limited by modest specificity, heterogeneous risk profiles, and inconsistent translation into effective cardioprotective interventions. This review synthesizes contemporary evidence on the biological mechanisms underlying cancer therapy-related cardiovascular toxicity and critically evaluates the current role and limitations of established cardiac biomarkers, including high-sensitivity cardiac troponins and natriuretic peptides, in risk stratification and early injury detection. We further examine why many cardioprotective clinical trials have yielded neutral or modest results, highlighting signal dilution arising from low-risk populations, endpoint heterogeneity, and timing mismatches between injury biology and intervention. This review advances a precision cardio-oncology framework by integrating tumor-derived liquid biopsy platforms-such as circulating tumor DNA, tissue-specific cell-free DNA, and extracellular vesicles-with cardiac biomarkers to provide a biologically contextualized assessment of cardiovascular risk. Tumor-derived biomarkers may reflect treatment intensity, systemic inflammatory burden, and cardiotoxic susceptibility, thereby enhancing the interpretation of cardiac biomarker signals and refining patient selection for targeted cardioprotective strategies.