The effects of FTO gene rs9939609 polymorphism on the association between breast cancer and dietary intake.

Breast cancer (BC) is the leading cause of cancer-related deaths in females worldwide and is related to genetic and environmental factors. Dietary components may strongly influence the risk of BC. A possible association was also reported between the fat mass and obesity-associated (FTO) single-nucleotide polymorphisms (SNPs) and BC. This study aimed to investigate the impact of FTO rs9939609 polymorphism on the association between BC and dietary intake. This study was conducted on 180 women with BC as the case group and 360 healthy women as the control group. The dietary intakes were assessed by a valid 168-item food frequency questionnaire (FFQ). The FTO gene was genotyped for rs9939609 polymorphism. After adjusting the confounding variables, there was no significant association between dietary intake and BC in individuals without risk allele. A positive association between dietary intake of omega-6 fatty acids and BC was found only in individuals with risk allele of FTO gene (OR: 1.31, 95% CI: 1.08-1.60, p: 0.006). FTO gene risk allele may influence the effect of diet on breast cancer risk. Further studies are needed to assess the possible effects of the FTO genotype on the association between BC risk and dietary components.