Proliferating Cell Nuclear Antigen Expression in Canine and Feline Spontaneous and Injection-site Fibrosarcomas

Fibrosarcoma, a tumor composed of spindloid fibroblasts, is grouped in soft tissue sarcomas which constitute one of the most important tumors in companion animals Cell proliferation index is a good indicator of the biological behavior of the tumors which is estimated either by mitotic index or cell proliferation markers. In the current study, we investigated the immunohistochemical expression of proliferating cell nuclear antigen (PCNA) in spontaneous and injection-site fibrosarcomas in dogs and cats. A positive correlation was noticed between the PCNA expression, mitotic index, tumor grade and degree of differentiation of the tumor cells in tumors from both of these species. PCNA expression was significantly different between different tumor grades in dogs and cats. It can be concluded from this study that PCNA is a useful marker for predicting the outcome of the canine and feline fibrosarcomas. (C) 2020 PVJ. All rights reserved