Clinical validation of a next-generation sequencing-based multi-cancer early detection “liquid biopsy” blood test in over 1,000 dogs using an independent testing set: The CANcer Detection in Dogs (CANDiD) study
Authors: Flory Andi , Kruglyak Kristina M. , Tynan John A. , McLennan Lisa M. , Rafalko Jill M. , Fiaux Patrick Christian , Hernandez Gilberto E. , Marass Francesco , Nakashe Prachi , Ruiz-Perez Carlos A. , Fath Donna M. , Jennings Thuy , Motalli-Pepio Rita , Wotrang Kate , McCleary-Wheeler Angela L. , Lana Susan , Phillips Brenda , Flesner Brian K. , Leibman Nicole F. , LaDue Tracy , Tripp Chelsea D. , Coomber Brenda L. , Woods J. Paul , Miller Mairin , Aiken Sean W. , Wolf-Ringwall Amber , Borgatti Antonella , Kraska Kathleen , Thomson Christopher B. , Kosanovich Cahalane Alane , Murray Rebecca L. , Kisseberth William C. , Camps-Palau Maria A. , Floch Franck , Beaudu-Lange Claire , Klajer-Peres Aurélia , Keravel Olivier , Fribourg-Blanc Luc-André , Mazetier Pascale Chicha , Marco Angelo , McLeod Molly B. , Portillo Erin , Clark Terry S. , Judd Scott , Feinberg C. Kirk , Benitez Marie , Runyan Candace , Hackett Lindsey , Lafey Scott , Richardson Danielle , Vineyard Sarah , Tefend Campbell Mary , Dharajiya Nilesh , Jensen Taylor J. , van den Boom Dirk , Diaz Luis A. , Grosu Daniel S. , Polk Arthur , Marsal Kalle , Hicks Susan Cho , Lytle Katherine M. , Holtvoigt Lauren , Chibuk Jason , Chorny Ilya , Tsui Dana W. Y. 
Published: April 2022

Cancer is the leading cause of death in dogs, yet there are no established screening paradigms for early detection. Liquid biopsy methods that interrogate cancer-derived genomic alterations in cell-free DNA in blood are being adopted for multi-cancer early detection in human medicine and are now available for veterinary use. The CANcer Detection in Dogs (CANDiD) study is an international, multi-center clinical study designed to validate the performance of a novel multi-cancer early detection “liquid biopsy” test developed for noninvasive detection and characterization of cancer in dogs using next-generation sequencing (NGS) of blood-derived DNA; study results are reported here. In total, 1,358 cancer-diagnosed and presumably cancer-free dogs were enrolled in the study, representing the range of breeds, weights, ages, and cancer types seen in routine clinical practice; 1,100 subjects met inclusion criteria for analysis and were used in the validation of the test. Overall, the liquid biopsy test demonstrated a 54.7% (95% CI: 49.3–60.0%) sensitivity and a 98.5% (95% CI: 97.0–99.3%) specificity. For three of the most aggressive canine cancers (lymphoma, hemangiosarcoma, osteosarcoma), the detection rate was 85.4% (95% CI: 78.4–90.9%); and for eight of the most common canine cancers (lymphoma, hemangiosarcoma, osteosarcoma, soft tissue sarcoma, mast cell tumor, mammary gland carcinoma, anal sac adenocarcinoma, malignant melanoma), the detection rate was 61.9% (95% CI: 55.3–68.1%). The test detected cancer signal in patients representing 30 distinct cancer types and provided a Cancer Signal Origin prediction for a subset of patients with hematological malignancies. Furthermore, the test accurately detected cancer signal in four presumably cancer-free subjects before the onset of clinical signs, further supporting the utility of liquid biopsy as an early detection test. Taken together, these findings demonstrate that NGS-based liquid biopsy can offer a novel option for noninvasive multi-cancer detection in dogs.