Combined effects of peroxisome proliferator-activated receptor alpha and apolipoprotein E polymorphisms on risk of breast cancer in a Taiwanese population.

Background: The peroxisome proliferator-activated receptor alpha (PPARA) and apolipoprotein E (APOE) proteins are reported to be correlated with lipid metabolism, cardiovascular disease, and breast cancer.

Methods: We screened APOE and PPARA (S24F and V227A) polymorphisms in 306 breast cancer patients and 300 noncancer controls and determined the relationship between their genetic polymorphisms and breast cancer risk. Interactions with clinical characteristics were also examined.

Results: We found that the risk of breast cancer was associated with APOE genotypes (P = 0.014) but not with PPARA S24F or V227A genotypes. The combined effects of F24/APOE genotypes (P = 0.003) on breast cancer risk were more significant than the individual effect of APOE genotypes (P = 0.014). F24/ε4 carriers had a higher tendency to develop breast cancer than F24/ε3 carriers (P = 0.013), and this effect is stronger than with individual ε4 carriers (P = 0.029). In addition, both F24/ε4 and V227/ε4 carriers were significantly enriched in the human epidermal growth factor receptor 2/neu negative status.

Conclusions: These findings suggest that the APOE ε4 genotype plays a major role in the prediction of breast cancer, but the PPARA F24 mutation enhances this outcome. The combined effects of F24/ε4 genotypes are positively associated with risk of breast cancer.