NCOG-30. FACTORS ASSOCIATED WITH COGNITIVE IMPAIRMENT IN LONG-TERM IDH-MUTANT GLIOMA SURVIVORS

Abstract BACKGROUND Cognitive deficits are less frequent in patients with IDH mutant (IDHm) than wild-type glioma at time of diagnosis, but less is known about factors that influence cognition for long-term survivors. We evaluated long-term neuropsychological outcomes of patients with IDHm glioma. METHODS Patients with IDHm glioma who underwent clinical neuropsychological assessment at Massachusetts General Hospital 3+ years after diagnosis were included and compared to a previously published cohort of IDHm patients tested prior to surgery/diagnosis (Wefel et al., 2016). RESULTS Sixty-three patients were included for analysis (54% male; median age 45 [range 21-75], 16 years of education, and 7 years from diagnosis [range 3-28]). Thirty-eight patients (60%) had astrocytoma and 24 (40%) had oligodendroglioma; 28 (44%) were grade 2, 31 (49%) grade 3, and 4 (6%) grade 4. Fifty-five patients (87%) received radiation and 51 (81%) received chemotherapy. Cognitive impairment (defined as Z score ≤-1.5 on at least two tests) was present in 30 patients (48%) and was associated with lower scores in neurologic aspects of quality of life (QoL; p<0.01), grade 3/4 relative to grade 2 (p=0.01), older age (p=0.03), left-sided lateralization (p=0.02), and less education (p=0.01). Prior radiation (p=0.07) and photon relative to proton radiation (p=0.06) trended toward poorer function. Tumor type, disease duration, and extent of resection were not significant factors (p>0.05). Compared to the pre-diagnosis IDHm cohort, impairment was significantly more common on tests of processing speed and language. Learning/memory, executive, and visuospatial function trended toward more frequent impairment but were not significant. Attention had comparable frequency of impairment. CONCLUSIONS In this cohort of IDHm glioma survivors, neurocognitive deficits were common, related to QoL, and associated with some expected clinical factors, but not length of survival. These findings emphasize the need for future research on interventions aimed at supporting patients’ neurocognitive abilities and QoL.