Study Of BRCA1 Mutations In Patients With Triple Negative Breast Cancer In Xinjiang

Objective:To understand the status of BRCA1 gene mutation and discuss differences of the clinical and pathological features between patients of BRCA1 gene mutation group and BRCA1 gene no mutation group by detecting the prevalence of BRCA1 mutations among triple negative breast cancer(TNBC) patients in Xinjiang. Methods:The objects of this study were 130 TNBC cases in Xinjiang. Genomic DNA was extracted from blood, and BRCA1 mutations were detected by combined use of PCR and direct sequencing. Results:(1)The prevalence of BRCA1 mutations in 130 TNBC cases was 17.7%(23/130), and the mutation rate of Han and minority patients respectively were 20.5%(17/83) and 12.8%(6/47), but there was no significant difference(?2=1.856, P=0.869). (2) 19 loci of 23 BRCA1 gene mutation cases were detected in 130 TNBC cases,in which 8 new loci were firstly detected; 4 repeated BRCA1 gene mutation were found.In addition,9 cases of pathogenic mutations were detected(6.9%,9/130),including 5 cases of nonsense mutations and 4 cases of frameshift mutations.(3)The prevalence of BRCA1 mutations in 46 early onset breast cancer cases was 28.3%(13/46), which was higher than that in late onset group (11.9%,10/84), and there was significant difference (?2=5.460, P<0.05). (4)Compared with patients of BRCA1 no mutation, patients of BRCA1 mutation had earlier age of onset, higher rate of axillary lymph node metastasis and later of TNM stage(P<0.05). Conclusion:(1) The prevalence of BRCA1 mutations in TNBC patients is higher in Xinjiang. (2) BRCA1 gene mutation rate of Han and minority patients with TNBC was no significant difference in the Xinjiang region.(3) Differences exist in the clinical and pathological features between patients of BRCA1 gene mutation group and BRCA1 gene no mutation group. (4) The discovery of the repeated BRCA1 gene mutation may be the gene mutation "hot", further studies are needed to expand the sample.