Association between ABCB1, ABCG2 carrier protein and COX-2 enzyme gene polymorphisms and breast cancer risk in a Turkish population

Aim: Breast cancer is the most common cancer and the second leading cause of cancer-related deaths among women. Several genetic and environmental factors are known to be involved in breast cancer pathogenesis, but the exact etiology of this disease is complicated and not completely understood. We aimed to investigate whether the gene polymorphisms of ABCB1 and ABCG2 carrier proteins and COX-2 enzyme affect breast cancer risk. Method: ABCG2 C421A (rs2231142), ABCB1 C3435T (rs1045642), COX-2 T8473C (rs5275) and COX-2 G306C (rs5277) were genotyped 104 breast cancer patients and 90 healthy controls using a real-time PCR for breast cancer susceptibility. Results: Patients carrying ABCG2 C421A, the CC genotype, had a higher risk of disease compared with patients carrying any A allele (OR = 3.06; 95% CI = 1.49–6.25, p = 0.0019). The other variants showed no association with breast cancer (p > 0.05). Comparing the pathological parameters with the variants, only, the frequency of C allele of ABCB1 C3435T was significantly lower in the estrogen receptor-α (ERα) (OR = 2.25; 95% CI: 0.75–6.76; p = 0.041) and progesterone receptor (PgR) (OR = 3.67; 95% CI: 1.34–10.03; p = 0.008) positive breast cancer patients. Conclusion: ABCB1 C3435T and ABCG2 C421A might represent a potential risk factor for breast cancer for Turkish women. Keywords: MDR1, BCRP, COX-2, Breast cancer, Genetic susceptibility, Genotype analysis