TP53 gene mutations in canine osteosarcoma

Objective-To investigate mutations of the TP53 gene in canine osteosarcoma (OS). Study Design-Clinical historic cohort study. Animals-Client-owned dogs. Methods-OS (n = 59) were screened for mutations of the complete TP53 gene using polymerase chain reaction and the mutation was analyzed by single-strand conformational polymorphism. Clinical outcome of dogs with TP53-mutated OS were compared with dogs with OS without a mutation after complete surgical excision of the primary tumor. Results-TP53 gene mutations were observed in 24 of 59 (40.7%) OS; 3 mutated OS had 2 mutations. The alterations consisted mainly of point mutations (74%). Dogs with mutated OS had a significantly shorter survival time (ST) after surgery than dogs with normal tumor TP53 gene expression (P=.03). Other significant prognosticators for ST and disease-free interval included elevated serum alkaline phosphatase (P<.01) and tumor grade (P=.01). Conclusion-TP53 genetic mutations are common in canine OS and may have a prognostic value. Clinical Relevance-Mutations of the TP53 gene may influence survival and should be considered when evaluating canine OS. (C) Copyright 2008 by The American College of Veterinary Surgeons.