Survival time following hospital discharge in dogs with palliatively treated primary brain tumors
- Autores: John H. Rossmeisl, Jeryl C. Jones, Kurt L. Zimmerman, John L. Robertson
- Localización: JAVMA: Journal of the American Veterinary Medical Association, ISSN-e 0003-1488, Vol. 242, Nº. 2, 2013, págs. 193-198
- Idioma: inglés
- Enlaces
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Resumen
Objective—To analyze survival time and identify prognostic factors associated with outcome following discharge in dogs with primary brain tumors treated palliatively.
Design—Prospective case series.
Animals—51 dogs with 5 histopathologic types of brain tumors.
Procedures—Owners with dogs examined from 2004 to 2008 were invited to participate if dogs had CT or MRI evidence of a brain mass that was histopathologically confirmed as a neoplasm upon death, dogs survived for ≥ 48 hours after hospital discharge, and treatments following discharge were limited to administration of prednisone or phenobarbital. Prognostic factors, including signalment, clinical signs (including duration), tumor type, tumor location, degree of peritumoral edema, lesion burden, and prescribed treatment, were evaluated. Survival time was estimated and animal- and tumor-specific variables evaluated as potential prognostic factors.
Results—The median survival time in all dogs was 69 days (95% confidence interval [CI], 18 to 201 days). Multivariate analyses identified neuroanatomic location as the only significant prognostic variable, with the survival time of dogs with infratentorial tumors (n = 18) being significantly shorter (median, 28 days; 95% CI, 19 to 68 days) than survival time of dogs with supratentorial (33) tumors (median, 178 days; 95% CI, 119 to 270 days). Seizures were the most common clinical sign associated with supratentorial tumors (24/33 [73%]) and central vestibular dysfunction with infratentorial tumors (12/18).
Conclusions and Clinical Relevance—Dogs with palliatively treated primary brain tumors, particularly those with tumors in the cerebellum, pons, or medulla, had a poor prognosis. However, dogs with supratentorial tumors had survival times > 3 months.
Dogs develop intracranial neoplasms more commonly than other large domesticated animal species and humans, and brain tumors are a common etiology of neurologic dysfunction referable to the brain in middle-aged to geriatric dogs.1–5 In necropsy-based studies,3,4 intracranial neoplasms account for 1% to 3% of all canine deaths, with secondary intracranial tumors being more prevalent than primary tumors. Several studies1–3 have identified meningiomas and gliomas (astrocytomas and oligodendrogliomas) as the most common canine primary brain tumors.
Despite the frequency with which intracranial neoplasms are diagnosed in clinical practice, there is currently little comparative information available regarding the influence of various treatment modalities, including purely palliative treatment, on the survival time of dogs with brain neoplasms. Although corticosteroids and anticonvulsants have been shown to transiently improve clinical signs and tumor-associated secondary complications (ie, peritumoral edema) in dogs with spontaneous and experimentally induced brain tumors, palliative treatments are universally associated with poor survival times in existing reports,1,2,6 with median survival times ranging from approximately 30 to 90 days in dogs with primary brain tumors.
It has been established that irradiation or gross, complete macroscopic resection of intracranial tumors, either alone or in combination, can provide a significant survival time benefit to dogs with a variety of intracranial neoplasms, including meningiomas, pituitary tumors, and gliomas.2,5,7–17 However, interpretation of survival time data in some studies,2,5,7–13 particularly those that specifically examine radiotherapeutic treatments, is complicated by the fact that histopathologic diagnoses were not stringent inclusion criteria, preventing analysis of tumor type on survival time or leaving the possibility that some treated lesions were nonneoplastic conditions.
Few canine studies have investigated prognostic factors in dogs with histopathologically confirmed tumors, and results of those studies1,2 provide ambiguous information regarding the influence of tumor-associated variables such as lesion burden or histopathologic type and grade. However, the severity of neurologic dysfunction and multifocal or infratentorial neuroanatomic tumor locations have been previously and negatively associated with survival time in existing canine studies.2,12,15 The purposes of the study reported here were to analyze overall survival time and identify prognostic factors in a cohort of dogs with histologically confirmed primary intracranial neoplasms that received palliative treatments.
