Association of Obesity Related Genetic Variants (FTO and MC4R) with Breast Cancer Risk:a population-based case-control study in Iran

Background: The heterogeneous breast cancer is the most common cause of cancer-related mortality. Obesity defined by BMI is known as a major risk factor for breast cancer. Objective: The purpose of this study was to explore the role of obesity related-polymorphisms rs9939609 FTO and rs17782313 MC4R in breast cancer development. Materials and Methods: We obtained matched peripheral blood, serum from 64 breast cancer patients and 83 normal controls. Height and weight were measured to calculate body mass index (BMI). All were genotyped for the SNPs rs9939609 and rs17782313 using a Tetra- primer ARMS-PCR method. For statistical analysis, Chi-square test and SPSS software were used. Results: In subgroup analyses defined by BMI, FTO rs9939609 genotypes (TT/AA/AT) were significantly associated with the risk of breast cancer only in non- obese subject (P < 0.005). TT genotype of MC4R rs17782313 in non-obese and genotypes TT/CC in overweight group were also statistically associated with breast cancer (P < 0.005). No significant associations between any variants and breast cancer risk were seen in obese subjects. Conclusion: Based on absence of association between obesity-related SNPs and breast cancer in obese subjects, we propose that weight gain in Iranian women will help prevent breast cancer risk.