The relationship of APOE genotype to neuropsychological performance in long-term cancer survivors treated with standard dose chemotherapy.

PURPOSE

The primary purpose of this study was to compare the neuropsychological performance of long-term survivors of breast cancer and lymphoma treated with standard dose chemotherapy who carried the epsilon 4 allele of the Apolipoprotein E (APOE) gene to those who carry other APOE alleles.

PATIENTS AND METHODS

Long-term survivors (mean=8.8+/-4.3 years post-treatment) of breast cancer (N=51, age=55.9+/-8.8) or lymphoma (N=29, age=55.8+/-11.6) who had been treated with standard-dose chemotherapy completed a standardized battery of neuropsychological and psychological tests. Survivors were also classified into two groups based on the presence (N=17) or absence (N=63) of at least one epsilon 4 allele of APOE.

RESULTS

Analysis of covariance, controlling for age, gender, education, diagnosis, and WRAT-3 reading subtest (a proxy measure of baseline IQ), indicated that survivors with at least one epsilon 4 allele scored significantly lower in the visual memory (p<0.03) and the spatial ability (p<0.05) domains and tended to score lower in the psychomotor functioning (p<0.08) domain as compared to survivors who did not carry an epsilon 4 allele. No group differences were found on depression, anxiety, or fatigue.

CONCLUSIONS

The results of this study provide preliminary support for the hypothesis that the epsilon 4 allele of APOE may be a potential genetic marker for increased vulnerability to chemotherapy-induced cognitive decline.