Substitutions of the NBS1 gene and clinicopathological characteristics of young breast cancer patients

Abstract

The purpose of this study was to determine characteristics potentially related to NBS1 mutations and polymorphisms in young (≤50 years of age) breast cancer patients. Blood from 80 breast cancer patients was collected. NBS1 mutations c.657_661del, p.R215W, p.I171V, and polymorphisms c.8360G>C, c.30537G>C were genotyped by the PCR-RFLP method. Two-sided Chi-square test was used for univariate analysis and logistic regression analysis was used to evaluate the odds ratio. No carriers of the c.657_661del, p.R215W and p.I171V mutations were found. NBS1 c.8360G>C logistic regression analysis showed that GC and CC genotypes compared with GG genotype had decreased risk of low grade tumour, 2.885-fold (OR = 2.885, 95% CI 0.173–0.735, P = 0.005) and 2.186-fold (OR = 2.186, 95% CI 0.188–0.888, P = 0.024), respectively. 8360 CC genotype (OR = 3.034, 95% CI 0.156–0.778, P = 0.010) significantly increased the chances of HER2 amplification compared to GG genotype. NBS1 8360 GC genotype had a higher risk for breast cancer progression (OR = 1.673, 95% CI 0.233–0.915, P = 0.027). The homozygote 8360 CC carriers had approximately a six times higher risk for the disease progress (OR = 5.946, 95% CI 0.098–0.585, P = 0.002). The prevalence of triple negative breast cancer type was significantly higher in individuals with NBS1 8360 CC genotype (OR = 2.186, 95% CI 0.188–0.888, P = 0.024). Regarding c.30537G>C polymorphism, none of the genotypes had a significant influence on pathological characteristics. NBS1 gene c.8360G>C polymorphism might be associated with breast cancer aggressiveness in young breast cancer patients.