Melanoma represents a significant malignancy in humans and dogs.,Different from genetically engineered models, sporadic canine melanocytic neoplasms share several characteristics with human disease that could make dogs a more relevant preclinical model.,Canine melanomas rarely arise in sun-exposed sites.,Most occur in the oral cavity, with a subset having intra-epithelial malignant melanocytes mimicking the in situ component of human mucosal melanoma.,The spectrum of canine melanocytic neoplasia includes benign lesions with some analogy to nevi, as well as invasive primary melanoma, and widespread metastasis.,Growing evidence of distinct subtypes in humans, differing in somatic and predisposing germ-line genetic alterations, cell of origin, epidemiology, relationship to ultraviolet radiation and progression from benign to malignant tumors, may also exist in dogs.,Canine and human mucosal melanomas appear to harbor BRAF, NRAS, and c-kit mutations uncommonly, compared with human cutaneous melanomas, although both species share AKT and MAPK signaling activation.,We conclude that there is significant overlap in the clinical and histopathological features of canine and human mucosal melanomas.,This represents opportunity to explore canine oral cavity melanoma as a preclinical model.
This retrospective study aimed to identify prognostic factors in patients with brain metastases from cutaneous melanoma.,In all, 265 patients under regular screening according to valid national surveillance guidelines were included in the study.,Kaplan-Meier analyses were performed to estimate and to compare overall survival.,Cox modeling was used to identify independent determinants of the overall survival, which were used in explorative classification and regression tree analysis to define meaningful prognostic groups.,In total, 55.5% of our patients presented with two or less brain metastases, 82.6% had concurrent extracranial metastasis and 64% were asymptomatic and diagnosed during surveillance scans.,In all, 36.7% were candidates for local treatment (neurosurgery or stereotactic radiosurgery (SRS)).,The median overall survival of the entire collective was 5.0 months (95% confidence interval: 4.3-5.7).,Favourable independent prognostic factors were: normal pre-treatment level of serum lactate dehydrogenase (P<0.001), administered therapy (neurosurgery or SRS vs other, P=0.002), number of brain metastases (single vs multiple, P=0.032) and presence of bone metastasis (false vs true, P=0.044).,Three prognostic groups with significantly different overall survival were identified.,Candidates for local treatment (group I) had the longer median survival (9 months).,Remaining patients could be further classified in two groups on the basis of serum lactate dehydrogenase.,Applied treatment and serum lactate dehydrogenase levels were independent predictors of survival of patients with brain metastases from cutaneous melanoma.,Patients receiving local therapy have overall survival comparable with general stage IV melanoma patients.