Cancer detection in clinical practice and using blood‐based liquid biopsy: A retrospective audit of over 350 dogs

Abstract

Background Guidelines‐driven screening protocols for early cancer detection in dogs are lacking, and cancer often is detected at advanced stages. Hypothesis/Objectives To examine how cancer typically is detected in dogs and whether the addition of a next‐generation sequencing‐based “liquid biopsy” test to a wellness visit has the potential to enhance cancer detection. Animals Client‐owned dogs with definitive cancer diagnoses enrolled in a clinical validation study for a novel blood‐based multicancer early detection test. Methods Retrospective medical record review was performed to establish the history and presenting complaint that ultimately led to a definitive cancer diagnosis. Blood samples were subjected to DNA extraction, 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 In an unselected cohort of 359 cancer‐diagnosed dogs, 4% of cases were detected during a wellness visit, 8% were detected incidentally, and 88% were detected after the owner reported clinical signs suggestive of cancer. Liquid biopsy detected disease in 54.7% (95% confidence interval [CI], 49.5%‐59.8%) of patients, including 32% of dogs with early‐stage cancer, 48% of preclinical dogs, and 84% of dogs with advanced‐stage disease. Conclusions/Clinical Importance Most cases of cancer were diagnosed after the onset of clinical signs; only 4% of dogs had cancer detected using the current standard of care (i.e., wellness visit). Liquid biopsy has the potential to increase detection of cancer when added to a dog's wellness visit.

Study Design and Interim Analysis of the Cancer Lifetime Assessment Screening Study in Canines (CLASSiC): The First Prospective Cancer Screening Study in Dogs Using Next-Generation Sequencing-Based Liquid Biopsy

“…This is in contrast to the cancer detection paradigm in current clinical practice: a recent analysis of >350 dogs with cancer found that only 4% had their disease detected at a routine wellness visit. 2 Of the 51 dogs diagnosed with cancer during the study period, 22 had false negative results from NGSbased liquid biopsy testing. As previously discussed, the detection rate of this type of testing varies by cancer type due to a variety of potential factors, including tumor size, extent of disease, and anatomic location.…”

“…This is in contrast to the cancer detection paradigm in current clinical practice: a recent analysis of >350 dogs with cancer found that only 4% had their disease detected at a routine wellness visit. 2…”

“…Overall, 6 of the 51 cancer cases were detected preclinically solely due to findings during a wellness visit or other routine care, consistent with a previously reported observation. 2 An additional 22 of the 51 cancer cases were detected preclinically due to a workup prompted solely by a CSD OncoK9® result.…”

“…8 A separate study, involving a subset of subjects from the CANDiD study, showed that NGS-based liquid biopsy has the ability to detect cancer preclinically, as well as at an early disease stage, making it a promising tool to increase early cancer detection when added to a wellness visit. 2…”

“…1 Historically, cancer screening in dogs has relied primarily upon the annual or semi-annual wellness visit; however, in most dogs cancer is detected after the development of clinical signs, often when the disease is advanced. 2 Early detection through screening offers the best chance of improving outcomes for dogs with cancer. 3,4 In 2021, a blood-based cancer detection test, OncoK9®, became clinically available for dogs.…”