Veterinary session

Coagulation abnormalities are often observed in canine oncology patients and are thought to correlate with disease progression and neoplastic severity. This can be explained by the cancer direct effect on the coagulation pathways or indirect effect through the inflammatory response of the body to the tumor.

Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT) are widely used coagulation assays, both in human and veterinary medicine, which measure different pathways of the clotting cascade. In human oncology these markers are used for monitoring cancer patients who are at risk of coagulopathies or thromboembolic events and for managing anticoagulation therapy. In contrast, their use in veterinary oncology is growing but has not been established yet. While PT and aPTT are used for monitoring coagulation in veterinary oncology patients, their prognostic value for cancer-related coagulopathies is still under investigation. Studies have suggested that prolonged clotting times are associated with advanced-stage cancers and may predict worsened outcomes, thus, this study aims to evaluate the potential of PT and aPTT as predictive markers for disease progression in canine oncology patients.

We conducted a retrospective analysis on more than 100 canine cancer patients presented to Á.H.O.K. Állatorvosi Hematológiai és Onkológiai Központ, Állatpatika. We assessed PT and aPTT values in relation to tumor type, stage, metastasis and clinical outcomes. In addition, paraneoplastic findings, particularly the presence of inflammatory processes, were detected. The statistical analyses will be provided in the thesis.

According to our hypothesis, prolonged PT and aPTT are associated with hypocoagulable state, often driven by disseminated intravascular coagulation (DIC), in advanced or aggressive cancers. Moreover, isolated prolongation of PT or aPTT suggests involvement of the extrinsic or intrinsic pathway, respectively. Conversely, shortened PT and aPTT are linked to hypercoagulable state, likely associated with systemic inflammatory response and increased thrombin generation induced by the tumor. Additionally, mixed coagulopathies, where PT and aPTT fluctuate over time, may occur in patients with advanced or metastatic disease. These differences may be caused due to changes in the tumor burden, inflammatory responses or as side effects of the treatments.

These findings suggest that monitoring of PT and aPTT in canine oncology patients could provide valuable predictive information. Future studies are needed to further establish the value of these tests as reliable prognostic markers for cancer related coagulopathies in dogs.