Cancer detection in dogs using rapid Raman molecular urinalysis

John L. Robertson^{1, 2*} Nikolaos Dervisis^{3, 4} John H. Rossmeisl³ Marlie Nightengale³ Daniel Fields³ Cameron Dedrick³ Lacy Ngo¹ Amr S. Issa^{1, 2} Georgi Guruli⁵ GIUSEPPE ORLANDO⁶ Ryan S. Senger^{1, 2*}

• ¹Virginia Tech, United States
• ²Rametrix Technologies, Inc., United States
• ³Virginia Maryland College of Veterinary Medicine, Virginia Tech, United States
• ⁴Virginia Tech Carilion, United States
• ⁵Virginia Commonwealth University Health System, United States
• ⁶Wake Forest Baptist Medical Center, United States

The presence of cancer in dogs was detected by Raman spectroscopy of urine samples and chemometric analysis of spectroscopic data. Urine samples were collected via voiding, cystocentesis, or catheterization from 89 dogs with no history or evidence of neoplastic disease, 100 dogs diagnosed with cancer, and 16 dogs diagnosed with nonneoplastic urinary tract or renal disease. Raman spectra were obtained of the unprocessed bulk liquid urine samples and were analyzed by ISREA, principal component analysis (PCA), and discriminant analysis of principal components (DAPC) were applied using the Rametrix ® Toolbox software. The procedure created a multimolecular spectral fingerprint with hundreds of features related directly to the chemical composition of the urine specimen. These were then used to detect the broad presence of cancer in dog urine as well as the specific presence of lymphoma, urothelial carcinoma, osteosarcoma, and mast cell tumor. The procedure identified a spectral fingerprint for cancer in canine urine, resulting in a urine screening test with 92.7% overall accuracy for a cancer vs. cancer-free designation. The urine screen performed with 94.0% sensitivity, 90.5% specificity, 94.5% positive predictive value (PPV), 89.6% negative predictive value (NPV), 9.9 positive likelihood ratio (LR+), and 0.067 negative likelihood ratio (LR-). Raman bands responsible for discerning cancer were extracted from the analysis and biomolecular associations were obtained. The urine screen was more effective in distinguishing urothelial carcinoma from the other cancers mentioned above. Detection and classification of cancer in dogs using a simple, non-invasive, rapid urine screen (as compared to liquid biopsies using peripheral blood samples) is a critical advancement in case management and treatment, especially in breeds predisposed to specific types of cancer.