APOE polymorphisms and cognitive functions in patients with brain tumors.

Objective: The goal of this study was to assess whether the APOE ε4 allele and other APOE single nucleotide polymorphisms (SNPs) influence neuropsychological and neuroimaging outcomes in patients with brain tumors.

Methods: Two hundred eleven patients with brain tumors participated in the study. All patients completed standardized neuropsychological tests and provided a blood sample for APOE genotyping. Ratings of white matter abnormalities were performed on MRI scans. Patients were classified into 2 groups based on the presence (n = 50) or absence (n = 161) of at least one APOE ε4 allele. Additional APOE SNPs were genotyped in a subset of 150 patients.

Results: Patients with at least one APOE ε4 allele had significantly lower scores in verbal learning and delayed recall, and marginally significant lower scores in executive function, in comparison to noncarriers of an ε4 allele. Patients with at least one ε4 allele and history of cigarette smoking had significantly higher scores in working memory and verbal learning than ε4 carriers who never smoked. Nine additional APOE SNPs were significantly associated with attention and executive and memory abilities. There were no significant differences between ε4 carriers and noncarriers on the extent of white matter abnormalities on MRI.

Conclusions: The findings suggest that patients with brain tumors who are carriers of the APOE ε4 allele may have increased vulnerability to developing memory and executive dysfunction, and that additional SNPs in the APOE gene may be associated with cognitive outcome.