A - 141 The Relationship of Tumor Location and Treatment on Cognition in Long-Term IDH-Mutant Glioma Survivors

Abstract Objective Isocitrate dehydrogenase 1 mutation (IDH-M) denotes a distinct subtype of glioma which has a relatively favorable prognosis but nevertheless requires treatment including surgery, radiation and/or chemotherapy and the tumors inevitably recur. Factors influencing cognition in long-term survivors (LTS) of IDH-M have not been well characterized. We investigated factors affecting cognition in a cohort of well characterized of IDH-M LTS. Method Patients (N = 65; 98.5% Caucasian; 47.7% female; Mage = 47.51; Medu = 16.06) who were at least 3 years post-IDH-M diagnosis who completed neuropsychological assessment in the Neuro-oncology division at Massachusetts General Hospital were included. Tests of processing speed, working memory, episodic memory, and executive function were analyzed along with tumor, treatment, and individual difference factors relevant to cognition. Exploratory analyses were conducted to generate hypotheses regarding factors of interest. Results Tumor hemisphere affected delayed recall of word list learning Z-score (F = 4.00; p = 0.024; left = −1.41; right = −0.59). Tumor lobe affected visual learning (F = 3.11; p = 0.054; frontal = −0.594; temporal = −0.807; parietal = −1.983). There were no effects of treatment type (photon vs proton radiation; single vs multi-agent chemotherapy), presence of seizures, psychiatric diagnosis, tumor subtype (oligodendroglioma/astrocytoma), grade (2,3,4) or disease duration (Mean = 9.5y; min = 3y; max = 28.8y) on cognition. Conclusions In this heavily treated group of IDH-M glioma LTS referred for neuropsychological evaluation, typical lateralizing/localizing cognitive deficits were revealed. However, simple dichotomies may fail to capture relevant contributors to cognitive impairment. Integration with individual factors including premorbid cognition, radiation dosimetry and brain network connectivity may be necessary to predict cognitive trajectories and outcomes.