Diagnostic value of carcinoembryonic antigen, cancer antigen 15-3, and cell-free DNA as blood biomarkers in early detection of canine mammary tumor.

Introduction: Blood biomarkers play a crucial role in the diagnosis and prognosis of tumor. The present research was designed to study the diagnostic effect of serum biomarkers, namely carcino-embryonic antigen (CEA), cancer antigen 15-3 (CA15-3), and plasma biomarker viz., circulating cell-free DNA (cfDNA); and their correlation with cytological and histopathological results.

Methods: A total of 60 blood samples were collected. Out of which 36 samples were from the dogs affected with canine mammary tumors, and 24 samples were from the apparently healthy dogs. CEA and CA15-3 were estimated using Sandwich ELISA, and cfDNA was estimated by the ccfDNA kit. A significant Positive correlation was observed between tumor blood biomarker levels, cytology and histopathological grades of the tumors.

Results: We found that CA15-3 can be a more effective serum tumour biomarker than CEA for diagnosing canine mammary gland tumours. This finding showed a positive correlation with the clinical grade of the disease. The concentration of serum markers and cfDNA in animals affected with malignant mammary gland tumours was higher compared to the benign entity of tumours and healthy control groups. The ROC curve analysis revealed that the sensitivity (Se) and specificity (Sp) of CEA and CA15-3 biomarkers improved when used together. IN comparison to healthy controls, canines with both benign and malignant neoplasia showed significantly higher (p < 0.05) cfDNA concentrations.

Conclusion: This study highlights the role of blood tumor biomarkers for routine screening of animals in early diagnosis of tumors, further treatment, and prognosis.