PART as a Negative Outcome Modifier of Glioblastoma Treatment, A Case Report

Background: Severe neurocognitive decline is often seen in elderly glioblastoma patients after treatment with radiation and chemotherapy. But the mechanism behind their deterioration is unclear. We describe one such patient with concomitant primary age-related tauopathy (PART) in bilateral hippocampi. Case presentation: An 88-year-old woman experienced unsteadiness, memory loss, and slurred speech that was caused by an epithelioid glioblastoma with wild-type isocitrate dehydrogenase-1 and methylated promoter of O6-methylguanine-DNA methyltransferase. She was treated with gross total resection, followed by intensity-modulated radiotherapy and daily temozolomide. Shortly after starting treatment, she developed fatigue, anorexia, and neurocognitive impairment, which were refractory to corticosteroids. After two cycles of adjuvant temozolomide, she experienced impulsivity, disorientation, hallucinations, somnolence, and incontinence despite stable neuroimaging findings. Treatment was subsequently discontinued, and she died 20 months from the time of her glioblastoma diagnosis. Autopsy revealed tau-positive neurofibrillary tangles, but rare Aβ plaques, in the transentorhinal and entorhinal cortices of both hippocampi. These findings are consistent with a diagnosis of PART. Conclusions: Undiagnosed tauopathy could be a negative modifier of glioblastoma treatment. Identification of PART and other tauopathies as risk factors in the elderly population may be important to guide treatment decision.