The Current State of Clinical Application of Serum Biomarkers for Canine Lymphoma

Serum biomarkers of canine lymphoma activity for diagnosis, prognosis, and therapy monitoring have been of clinical interest for more than a decade. Tumor products, biochemical enzymes, cytokines, metabolic profiling, leakage enzymes, as well as serum proteins have been studied as biomarkers for lymphoma. Multiple biomarkers combined have been shown to be most sensitive and specific. C-reactive protein, thymidine kinase 1, and haptoglobin have been most extensively studied and commercialized in diagnostic tests, the TK Canine Cancer Panel and the Canine Lymphoma Blood Test. These tests have been evaluated either in cohorts of diseased and healthy dogs or in prospective studies of ill dogs, respectively, for application to clinical decision-making. Some evidence exists for application of these tests, but large-scale studies are lacking in a broad range of lymphoma forms. These biomarkers are commonly elevated at diagnosis and at relapse. Further study is necessary to determine if early intervention guided by biomarker elevation will improve quantity or quality of life for dogs with lymphoma.