Introduction

Cancer is the leading cause of death in dogs, with no established screening paradigms for early detection. As a result, many patients are diagnosed at an advanced stage, when clinical signs have developed and prognosis is poor. Liquid biopsy methods that interrogate cancer-derived genomic alterations in cell-free DNA fragments in blood are being adopted for early cancer detection in human medicine. Development and use of a noninvasive test for the early detection of cancer in dogs may lead to improved outcomes.

Methods

Blood samples from an all-comers cohort of 191 cancer-diagnosed dogs and 188 presumably cancer-free dogs were subjected to DNA extraction, proprietary library preparation, and next-generation sequencing. Sequencing data were analyzed using an internally developed bioinformatics pipeline to detect genomic alterations associated with the presence of cancer.

Results

The overall test sensitivity in cancer-diagnosed subjects was 48% (92/191). Of 188 samples from presumably cancer-free dogs, 180 tested negative (‘putative true negatives’) and 8 tested positive (‘putative false positives,’ pFP). In at least 2 pFP cases, patients were diagnosed with cancer 6 and 7 months following blood collection and were excluded from final performance analyses, resulting in a minimum test specificity of 97%.

Conclusion

A novel, multi-cancer early detection (MCED) liquid biopsy test has demonstrated the ability to identify cancer-associated genomic markers (in some cases months prior to the onset of clinical signs) in canine patients, with sensitivity and specificity comparable to commercially available MCED testing options in humans. Early detection and treatment of cancer are key determinants of optimal clinical outcomes.

Funding Information

This study received funding from PetDx.