RESUMO
BACKGROUND: Hepatocellular carcinoma (HCC) in dogs is uncommon and often associated with a good prognosis, although some cases prove to be aggressive. In human oncology HCC is often very aggressive and diagnostic methods and prognostic factors are widely used to predict its biological behaviour. These include the expression of PIVKA-II. METHODS: in order to identify a prognostic factor for canine HCC, we applied different methods of histological grading and investigated PIVKA-II expression in 22 HCC of dogs treated surgically and followed clinically for at least 2 years. RESULTS: Nineteen patients analysed have passed the observation period without tumour recurrence, while 3 died following the development of metastases. PIVKA-II was positive in 15/22 cases without correlation with prognosis or tumoural grading even if a trend of PIVKA-II negativity in low WHO grades as well as increased number of PIVKA-II positive cases in higher WHO grades weres observed. CONCLUSIONS: This work showed that, PIVKA-II cannot be considered either as a marker of malignancy or as a prognostic marker for canine HCC. The poor prognosis depends usually on the clinical presentation. Thus prognostic parameters in canine HCC able to predict its aggressive behaviour through histological examination are still missing. The most promising method, limited to our study, seems to be the WHO histological grading.
RESUMO
PIVKA-II is an aberrant form of vitamin K that has been demonstrated to be increased in human coagulation disorders and in some neoplastic diseases. In veterinary medicine, PIVKA-II levels have been demonstrated to be useful for distinguishing anticoagulant poisoning from other coagulopathies. In forensic pathology, there is the need to distinguish malicious poisoning from other causes of death and, in some cases, identifying poisoned dogs from dogs that died as a result of other coagulative disorders can be challenging. In this study, dogs that suddenly died underwent necropsy, histological examination, and toxicological analysis to establish cause of death. PIVKA-II immunohistochemical expression was evaluated on hepatic and renal tissues, and on neoplastic lesions when present. A total of 61 dogs were analyzed and anticoagulant substances were identified in 16 of the 61. Immunolabelling for PIVKA-II was observed in 27 of 61 cases in the liver and in 24 of 61 cases in the kidneys. Among the poisoned dogs, the PIVKA-II expression was present in the liver in 15 of 16 cases and in the kidneys in 16 of 16. Neoplastic lesions represented mainly by haemangiosarcomas were negative. This study highlights how the immunohistochemical expression of PIVKA-II in hepatic and renal tissues can be useful to identify patients with coagulative disorders due to clinical condition or the ingestion of anticoagulants substances.