Abstract
PURPOSE: We explored relationships between genetic variability and behaviorally related variables (body mass index and exercise frequency) for inflammation, and perceived cognitive function (PCF) for breast cancer survivors (BCS). Our primary aim was to explore relationships between select single-nucleotide polymorphisms (SNPs) for IL1R1, IL6, TNF genes, and PCF. Our secondary aim was to explore whether body mass index (BMI) and exercise frequency moderate these relationships. METHODS: We conducted an exploratory candidate gene substudy. Saliva samples from participants (N = 101) in a larger, cross-sectional study were genotyped. Multiple linear regression analysis was used to explore relationships between SNPs and PCF, controlling for age, education level, fatigue, and distress. Hierarchical expansion of regression models included main effects for BMI and exercise frequency and interaction effects between BMI, exercise frequency, and each SNP. RESULTS: The most parsimonious regression model included fatigue, exercise frequency, and IL1R1rs2287047 minor alleles (AA+GG) (R (2) = 0.244, adjusted R (2) = 0.220, p = 0.013). No other SNPs were significant. Higher exercise frequency (b = 7.300, p = 0.013) and IL1R1rs2287047 (AA+AG) (b = 6.512, p = 0.025) predicted better PCF. Greater fatigue predicted poorer PCF (b = -2.359, p < 0.01). No interaction was demonstrated between BMI and exercise related to PCF or between BMI, exercise, and SNPs. CONCLUSIONS: Our results suggest a protective relationship between IL1R1rs2287047 (AA+AG) and PCF and provide further evidence supporting exercise as a potential intervention for poorer PCF. Ours is the first study to investigate genetic variability associated with inflammation, behaviorally related variables, and PCF for BCS.