CYP17, CYP19, and NQO1 Genetic Polymorphisms and Breast Cancer Susceptibility in Young Women in Brazil

Aims: Breast cancer is the most common cancer in women worldwide, being exposure to estrogens the acknowledged main risk factor. CYP17, CYP19 and NQO1 are enzymes involved in the estrogen metabolism, so their polymorphisms may be involved in breast carcinogenesis. The aim of this study was to determine the magnitude of the association between CYP17 MspA1, CYP19 Arg264Cys, and NQO1 C609T polymorphisms and breast cancer in young women.
Methods: This is a hospital-based case-control study carried out in Rio de Janeiro. Cases were 270 women with age range 18-35 years and a histopathological diagnosis of breast cancer between 1999-2009. Controls were 270 women without cancer at the same age range.
Results: An association between CYP17 MspA1 or CYP19 Arg264Cys polymorphisms and breast cancer were not observed (OR = 1.02, 95% CI 0.72-1.44 for CYP17 genotypes TC/CC and OR = 0.85, 95% CI 0.48-1.49 for CYP19 genotypes CT/TT). However, a statistically significant increased risk estimate was identified in women who had at least one NQO1 polymorphic allele (T), OR= 1.96, 95% CI 1.13-3.40 following adjustment for selected confounders.
Conclusion: This study suggests that the NQO1 609T polymorphism may be a risk factor for breast carcinogenesis in women less than 36 years in Brazil.