Evaluation of the association between Val158Met polymorphism of COMT gene from estrogen metabolism pathway and risk of breast cancer

Breast Cancer (BC) is the most common cancer in women. Polymorphisms of some genes have been implicated in many diseases such as breast cancer. COMT involved in estrogen metabolism reduces activity by three to four times by altering valine amino acid to methionine and may be at risk for breast cancer. The aim of the present study was to investigate the association between Val158Met polymorphism of COMT gene and BC in a group of Iranian women. 

In the current case-control study, 96 patients and 96 healthy individuals were selected. The DNA of their white blood cells was extracted using salt saturation method and the genotypes of the participants were determined via RFLP-PCR. The data were analyzed using chi-square and logistic regression  tests. 

There was no statistically significant relationship between mean age and cigarette smoking. The AA mutant genotype had a statistically significant relationship between the two groups. Examination of dominant and recessive genetic models also revealed that this polymorphism is associated with a high risk of BC and increases the risk of breast cancer by 3.1 and 2.8, respectively, compared with the control group. Also, carriers of allele A were 3 times more likely to develop BC. 

This polymorphism appears to be related to the risk of breast cancer in Iranian women and the presence of the A allele may be considered as one of the  risk factors for breast cancer