What question did this study set out to answer?

To evaluate the OncoCan assay for the quantification of cell-free DNA in canine plasma and assess its diagnostic and prognostic utility.

February 26, 2026Open Access

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

Key Points

To evaluate the OncoCan assay for the quantification of cell-free DNA in canine plasma and assess its diagnostic and prognostic utility.
Analyzed plasma cfDNA samples from 83 dogs with neoplasms and 47 healthy controls.
Used Wilcoxon rank-sum testing to compare cfDNA concentrations in neoplastic versus healthy samples.
Conducted ROC curve analysis to determine diagnostic accuracy across different cancer types.
Established practical cfDNA concentration thresholds for prognostic interpretation.
Significantly higher cfDNA concentrations were found in dogs with neoplasms compared to healthy controls (p = 4.45e–07).
ROC analysis indicated high accuracy (AUC = 0.95) for lymphomas/leukemias and moderate accuracy for carcinomas (AUC = 0.75) and sarcomas (AUC = 0.76).
Three cfDNA thresholds were established: <50 pg/μL for distinguishing healthy from neoplastic cases, ≥100 pg/μL indicating aggressive disease, and ≥300 pg/μL associated with systemic dissemination.
The <50 pg/μL threshold showed robust diagnostic performance with an AUC of 0.808 and sensitivity of 82%.

Abstract

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: 50 pg/μL to distinguish healthy from neoplastic cases; ≥100 pg/μL as a “high positive” threshold indicating aggressive disease; and ≥300 pg/μL as a “very high positive” threshold strongly associated with systemic dissemination, high-grade histology, and poor survival. The 50 pg/μL cut-off showed robust diagnostic performance (AUC = 0.808, sensitivity = 82%, specificity = 73%), confirmed by survival analysis and hazard ratio modeling. These findings suggest that OncoCan provides a noninvasive, clinically applicable tool for cancer prognosis in dogs. Validation in larger cohorts is warranted to support its integration into routine veterinary oncology practice.

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