Prognostic relevance of selected nucleotide variants in canine cutaneous mast cell tumors

Multiple genetic variants of specific genes, such as KIT, GNAI2, and SETD2, have been reported in canine mast cell tumors (MCTs). A familiar internal tandem duplication of KIT in exon 11 is associated with poor prognosis. However, others common mutated genes in canine MCTs as increased risks to recurrence or death remain unexplored. This study investigated 39 genetic variants contributed to MCT-related risk factors and prognoses in paraffin shaved specimens from 38 low-grade and 34 high-grade MCTs using multiplex genotyping (MassARRAY, Agena Bioscience). The associations between observed genetic variants and prognostic factors were statistically analyzed. SETD2 c.1108_1109del tended to present in MCTs with aberrant expression of KIT (P = 0.05). GNB1 c.346_347delinsTA/TT wild types were likely to harbor in less aggressive MCTs (P = 0.007). MCT dogs having TP53 c.659 T > C were 1.65 times higher hazard risk on decreased time to recurrence by univariate analysis (95% CI 1.02-2.67, P = 0.041), but not in multivariate analysis. Our study suggests that SETD2 c.1108_1109del, and TP53 c.659 T > C may associate with poor prognosis; however, further study with larger samples is needed to confirm these correlations.