The Association of MDR1 (C3435T) Polymorphism and Cervical Cancer in Women Taking Oral Contraceptives

Abstract

Background and objectives: The multidrug resistance 1 gene (MDR1) plays an important role in function of P-gp to excrete toxins from cells. In humans, a nucleotide at position 3435 on exon 26 of MDR1 is polymorphic with 3 genotypes:  CC, CT and TT. An individual’s genotype may be associated with the risk of cancers. This study aimed to investigate the association between MDR1 (C3435T) and cervical cancer risk among women taking oral contraceptives.

Methods: A case-control study conducted in 169 invasive cervical cancer patients and 169 controls. Genetic polymorphism of MDR1 (C3435T) was analyzed from white blood cells by PCR-RFLP method. The association between MDR1 (C3435T) genotype and risk of cervical cancer was analyzed by logistic regression.

Results: It was found that individuals having MDR1 (C3435T) gene with the TT genotype was higher risk of cervical cancer 1.94 fold (95%CI: 1.07-3.51, p=0.028). Among subjects who taking contraceptive pills, the TT genotype could increase risk of cervical cancer development 2.70 fold (95%CI: 1.08-6.76, p=0.033). However, the association between genetic polymorphism of MDR1 (C3435T) and increased risk of cervical cancer was not observed in women who had smoking partners (p>0.05).

Conclusions: Our data suggest that MDR1 (C3435T) polymorphism may not a risk of cervical cancer in women who had smoking partners, whereas is associated with risk of cervical cancer among women who taking contraceptive pills. Therefore, investigation of genetic risk factors may be a useful method for screening women at high risk of cervical cancer.