Big endothelin-1 as a tumour marker for canine haemangiosarcoma.

Haemangiosarcoma (HSA) is an important malignant neoplasm of dogs that originates from vascular endothelial cells. This study explored the suitability of using serum big endothelin-1 (ET-1) as a tumour marker for canine spontaneous HSA. Serum big ET-1 was measured in dogs with splenic HSA ( n  = 14), splenic malignant tumours other than HSA ( n  = 10), benign splenic lesions ( n  = 11) and normal healthy dogs ( n  = 17) by ELISA. Serum big ET-1 levels in dogs with HSA were significantly ( P  < 0.01) higher than in other dogs. High sensitivity (100%, 95% confidence interval 86–100%) and specificity (95%, 95% confidence interval 86–95%) for HSA diagnosis were obtained using a cut-off of 17 pg/mL according to receiver operating characteristic (ROC) curves (area under ROC curve 0.93). PPET1 , ETA, VEGF and Hif1-α mRNA expression, measured by real-time PCR, were elevated in HSA compared with normal tissues. These findings suggest that elevated serum big ET-1 could be used as a diagnostic marker for canine HSA. [ABSTRACT FROM AUTHOR]