Canine thyroid carcinoma prognosis following the utilisation of computed tomography assisted staging

Abstract

BACKGROUND: Metastatic disease is frequently present at the time of diagnosis of canine thyroid carcinoma; however, utilisation of computed tomography (CT) alone for staging pre-treatment has been rarely reported in the veterinary literature. METHODS: The aims of this retrospective study were to stage affected dogs using CT findings of the cervical and thoracic regions, combined with histopathology/cytology results, in order to assess whether metastatic disease/WHO staging was of prognostic significance. RESULTS: Fifty-eight dogs were included in the study. Classification of cases into WHO stages I, II, III and IV were 10%, 50%, 9% and 31%, respectively. No statistically significant effect of WHO stage classification on overall survival/follow-up time was found (P = .576). Surgery resulted in a statistically significant increase in overall survival/follow-up time (P < .01). There was no statistically significant effect on overall survival/follow-up time in dogs that received medical therapy, either as sole therapy or as an adjunctive post-surgery (P = .198). CONCLUSION: In summary, this study documents the metastatic rate of canine thyroid carcinoma using CT for staging pre-treatment. Staging utilising CT revealed a higher distant metastatic rate in dogs with thyroid carcinoma when compared to historical studies using different imaging techniques. As long-term outcomes are possible for cases with advanced disease, surgical intervention could still be considered.