O10 - Clinico-Genomic Data of Dogs with Malignant Oral Melanoma

Background - Oral melanoma is an aggressive tumor in dogs characterized by high rates of local invasion and distant metastases. Local and systemic therapies have not been effective in controlling the disease and promoting longer survival times.
Hypothesis/Objective - The study aim was to evaluate the genetic mutational landscape of canine oral melanomas to identify genomic profiles and potential molecular targets for small molecules.
Animals - Sixty-nine client-owned dogs with confirmed oral melanoma enrolled in FidoCure® Precision Medicine Platform from May 2019 until December 2020.
Methods - Tumor samples were screened against a NGS panel of 57 oncogenes and tumor suppressor genes. Clinical information and treatment outcomes from dogs receiving targeted therapy based on the genomic profile were collected.
Results - KMT2C and CREBBP were the most commonly mutated genes at 26.08% and 17.4% of tumors, respectively. TP53 and NRAS mutations were identified in 14.5% and 13.04% of tumors, respectively, one dog had co-occurrence of both mutations. BRCA1 and BRCA2 mutations were each identified in 10.15% of tumors. Four dogs received small molecule targeted therapy only with a median survival time (MST) of 235 days, and 22 dogs had target therapy in conjunction with traditional treatment (MST = 263 days). Dogs previously treated with surgery had a longer survival time of 307 days compared to 175 days for dogs not treated with surgery (P = 0.0028).
Conclusion and Clinical Importance - Genomic data can potentially guide the use of small molecule targeted therapy as adjuvant treatment for dogs with malignant oral melanoma.