High COX-2 expression in canine mast cell tumours is associated with proliferation, angiogenesis and decreased overall survival.

COX-2 overexpression is associated with several hallmarks of carcinogenesis such as proliferation, angiogenesis, invasion and metastasis. Fifty cases of canine mast cell tumours ( MCT) were retrospectively evaluated and submitted to immunohistochemistry for COX-2, CD31, Ki-67, MAC-387 and CD3. Furthermore its relationship with clinicopathological variables and overall survival ( OS) was analysed. COX-2 intensity ( P = 0.016), but not COX-2 extension nor score was associated with decreased OS and higher grades of malignancy according to Patnaik ( P = 0.002) and Kiupel ( P < 0.001) grading systems. Cox-2 intensity was also associated with higher Ki-67 scores ( P = 0.009), higher mitotic index ( P = 0.022) and higher microvascularization density ( P = 0.045). No association was observed for COX-2 intensity and CD3-T lymphocyte ( P = 0.377) and macrophage infiltration ( P = 0.261) by MAC-387 immunollabelling, suggesting an active role of COX-2 in MCT oncogenesis mainly through proliferation and angiogenesis stimulation making it a potentially clinical relevant prognosis marker and therapeutic target. [ABSTRACT FROM AUTHOR]