OncoCan: a liquid biopsy assay for cell-free DNA quantification in canine plasma to support cancer prognosis

Early cancer detection remains a major challenge in veterinary medicine. Cell-free DNA (cfDNA), released into the bloodstream through apoptosis, necrosis, or circulating tumor cells, can be quantified non-invasively via liquid biopsy and is already established in human oncology. In this study, we evaluated OncoCan, a targeted plasma cfDNA assay, by analyzing samples from 83 dogs with various neoplasms and 47 healthy controls to assess diagnostic and prognostic utility. Wilcoxon rank-sum testing revealed significantly higher cfDNA concentrations in neoplastic versus healthy samples ( p = 4.45e–07). ROC curve analysis demonstrated high accuracy for lymphomas/leukemias (AUC = 0.95) and moderate accuracy for carcinomas (AUC = 0.75), sarcomas (AUC = 0.76), and melanomas (AUC = 0.69). Stratification by histological grade and clinical stage further supported cfDNA’s predictive capability. Three practical thresholds were established: