The results of the study suggest that NQO1 exon 6 proline187serine (C609T) and CYP1A2 exon 2 phenylalanine21leucine (C63G) polymorphisms do not play a significant role in breast cancer susceptibility in North Indian women.
Combining the two 'candidate' SNPs (P187S and R72P) revealed an increased risk for breast cancer of double heterozygotes (P187S/R72P) of the NQO1 and TP53 genes (OR=1.88; 95% CI 1.13-3.15; P=0.011), suggesting a possible interaction of these two loci.
We have previously found that homozygous missense variant NQO1*2 (rs1800566) predicts poor survival among breast cancer patients, particularly after anthracycline-based adjuvant chemotherapy.
We find that a homozygous common missense variant (NQO1(*)2, rs1800566(T), NM_000903.2:c.558C>T) that disables NQO1 strongly predicts poor survival among two independent series of women with breast cancer (P = 0.002, N = 1,005; P = 0.005, N = 1,162), an effect particularly evident after anthracycline-based adjuvant chemotherapy with epirubicin (P = 7.52 x 10(-6)) and in p53-aberrant tumors (P = 6.15 x 10(-5)).
In the stratified analysis by ethnicity, we found that the Pro187Ser polymorphism was associated with increased breast cancer risk in Caucasians in the additive genetic model and dominant genetic model (P = 0.03, OR = 1.13, 95% CI = 1.01-1.26; P = 0.03, OR = 1.15, 95% CI = 1.01-1.30, respectively), whereas no significant in Asians (P = 0.44, OR = 0.94, 95% CI = 0.80-1.10) and postmenopausal women (P = 0.99, OR = 1.00, 95% CI = 0.84-1.19).
The C609T (Pro187Ser) Null Polymorphism of the NQO1 Gene Contributes Significantly to Breast Cancer Susceptibility in North Indian Populations: a Case Control Study.