Biochemical and haemostatic variables associated with metastasis in dogs with carcinoma or sarcoma.

Objectives: Identify alterations in biochemical and haemostatic variables between tumour-bearing dogs with and without metastasis that can be used to predict the presence of metastasis.

Materials and methods: Thirty dogs with sarcoma and 29 with carcinoma were included in the analysis. Serum biochemistry profiles and haemostatic variables (haematocrit value, platelet count, thromboelastography (TEG), fibrinogen, Factor X, VII, antithrombin activity and D-dimer concentration) were measured for all dogs. All dogs underwent complete post-mortem and histopathological evaluations. For tumour-bearing dogs without intracavitary haemorrhage, measured variables were compared between dogs with and without metastasis, and univariate and multivariable analysis were performed to identify predictors of metastasis.

Results: Metastasis was identified in 31 of 59 (53%) dogs, of which 5 of 31 (16%) had metastasis to the regional lymph node only and 26 of 31 (84%) had distant metastasis. Sodium, ionised calcium, TEG lysis % at 30 and 60 minutes (Ly60) were significantly lower in tumour-bearing dogs without intracavitary haemorrhage with metastasis compared to dogs without metastasis. Multivariable analysis identified sodium <142.5 mmol/L as 64% sensitive (CI_95%:45% to 82%) and 63% specific (CI_95%:44% to 81%); and Ly60 < 1.0% as 68% sensitive (CI_95%: 49% to 88%) and 78% specific (CI_95%:61% to 95%) for prediction of the presence of metastasis. Parallel interpretation of lower sodium and decreased Ly60 resulted in high sensitivity (96%) for the presence of metastasis.

Clinical significance: Sodium and TEG-based decreased fibrinolysis were associated with metastasis in tumour-bearing dogs without haemorrhage; when identified, they should prompt further diagnostics to detect possible metastasis of a primary carcinoma or sarcoma.