Högskolan i Skövde

Breast cancer is one of the most common cancers in women worldwide. The estrogen receptor alpha (ESR1) and epidermal growth factor receptor (EGFR) have been known to play a vital role in development and progression of breast cancer. The aim of the present study was to determine the relationship, if any, between genetic polymorphism in (ESR1) 2014G>A (T594T) and (EGFR) 142285G>A (R521K) with risk of breast cancer and the prognosis in a heterogeneous North Indian population that is known for its diverse ethnicity. A case-control study in a total of 300 individuals comprising of 150 breast cancer patients and 150 normal controls was performed. PCR-RFLP was employed for genotyping. The G/A heterozygous genotype EGFR R521K, was slightly higher in cases (56.7 %) than in controls (48.3 %) (P = 0.20). The results indicated that EGFR polymorphism does not show any significant association with breast cancer in this population. On the other hand, the mutant A/A genotype ESR1 codon 594, showed a 6.4-folds risk for breast cancer and this association was highly significant (P = 0.00) as compared to wild GG genotype, the heterozygous G/A genotype also showed a significant association with disease (P = 0.00, OR = 2.03). In addition, the frequency of A allele was also higher in cases (36 %) than in controls (19 %) and a highly significant difference was observed with wild G allele (63.3 % in cases and 6.6 % in controls). This clearly indicates that there appears to be an influence of ESR1 codon 594 genotypes on genetic susceptibility to breast cancer. Further a significantly higher risk was observed in individuals who had diabetes {OR = 3.04 (1.68-5.50), P = 0.00} and females with ESR polymorphism in pre-menopause patients that had undergone menopause above the age of 50 years {OR = 3.58 (1.86-6.90), P < 0.05}. The different ethnic backgrounds and geographical locations have complimented the present genotypic analysis and have highlighted the influence of ethnicity, race and geographic location in genetic predisposition to breast cancer.