Survival times in dogs with presumptive intracranial gliomas treated with oral lomustine: A comparative retrospective study (2008-2017).

Intracranial gliomas are a common malignancy in dogs, and are associated with a poor prognosis due to their aggressive nature and a lack of clinically effective treatments. The efficacies of various treatment modalities for canine brain tumours have been previously described, though little data exist on the use of cytotoxic chemotherapy. A comparative retrospective study, including 40 cases from 5 northeastern US veterinary hospitals, from 2008 to 2017, was conducted. Variables analysed in this study with relation to overall survival and prognostic significance included: age, sex, clinical signs, clinical sign duration, tumour location and treatment protocol used. Dogs with presumptive intracranial gliomas treated with lomustine chemotherapy lived longer (median, 138 days) than those treated exclusively with symptomatic care (median, 35 days; P = .0026 log-rank, 0.0138 Wilcoxon). Additionally, a duration of clinical signs ≥16 days prior to diagnosis (median, 109 days) was associated with a longer survival than a duration <16 days prior (median, 25 days; P = .0100 log-rank, 0.0322 Wilcoxon). Lomustine-associated side effects included neutropenia in 46% of dogs, anaemia in 15% and thrombocytopenia in 15%. Potential renal and hepatotoxicity based on increased BUN and/or creatinine and ALT values were reported in 15% and 50% of dogs, respectively. This study provides evidence that lomustine therapy may be effective in prolonging survival in dogs with intracranial gliomas and should be considered as a potential treatment option. Although lomustine-related toxicities are fairly common, they are rarely life threatening and often do not result in discontinuation of therapy.

Association of prognostic features and treatment on survival time of dogs with systemic mastocytosis: A retrospective analysis of 40 dogs.

Systemic mastocytosis is a rare phenomenon, with limited information regarding prognostic features and effective treatment of canine patients with this disease. The objective of this study is to determine the impact of certain features and treatments on dogs with systemic mastocytosis. The medical records of 40 dogs from 4 northeastern US veterinary hospitals, with evidence of systemic mast cell disease, were evaluated retrospectively. Variables analysed with relation to overall survival and prognostic significance included treatment protocol used, substage, presence of a cutaneous or visceral tumour, presence of multiple cutaneous Mast cell tumours, grade of the primary tumour and metastatic site(s). Dogs with metastatic disease confined to distant lymph nodes lived longer than those with circulating mast cells in the blood (P = .001), and those with metastatic disease evident in more than 2 sites had a worse prognosis than those with disease in a single location (P = .005). Additionally, administration of chemotherapeutic agents led to increased survival over prednisone therapy alone (P = .008), with the combination of lomustine, vinblastine and prednisone prolonging survival over the tyrosine kinase inhibitor, toceranib phosphate (P = .002). Presence of mast cells in the blood and/or evidence of disease in more than 2 sites indicate widespread dissemination suggesting their use as negative prognostic features. Furthermore, a chemotherapy protocol including combination lomustine and vinblastine therapy may be more effective than toceranib phosphate for the treatment of dogs with disseminated mast cell disease. Overall, patients with systemic mastocytosis have a grave prognosis and more effective treatment options are needed.