ABSTRACT
Potential association of leptin [LEP] gene polymorphisms has been suggested in the processes leading to breast cancer initiation and progression. We investigated whether genetic variations in the LEP -2548G/A gene are associated with risk of breast cancer. This case-control study consisted of 100 breast cancer cases and 100 control subjects without breast cancer that matched for age and body mass index [BMI]. Genotyping of LEP -2548G/A polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism [PCR-RFLP] assay. Serum leptin level was determined by ELISA in all study subjects. The genotype distributions [AA, AG, and GG] were 36, 55, and 9% in breast cancer cases and 52, 45, and 3% in control group, respectively. The frequency of LEP -2548 GG genotype was significantly elevated in breast cancer cases as compared to controls [chi2=6.90, p=0.032]. Similar difference was also found in allele frequencies between two groups [chi2=5.65, p=0.017]. A markedly increase risk of breast cancer was associated with the LEP -2548GG genotype when compared to the LEP -2548 AA genotype [OR=4.33, 95% CI=1.09-17.22]. In addition, postmenopausal women who bear at least one LEP -2548 G allele were at a markedly increased risk of breast cancer after adjusting for age and BMI confounders [OR=12.24, 95% CI=1.13-131.73]. The LEP -2548 G/A polymorphism is associated with markedly increased risk of breast cancer especially in postmenopausal Ahvazian women and supported the hypothesis that leptin is involved in breast cancer