Detection And Analysis Of Relevant Factors On Xinjiang High-risk Hereditary Breast Cancer BRCA1/2Mutations,Promoter Methylation

Objective:(1) Through the detection of82cases of high risk of hereditary breast cancer BRCA mutation in Xinjiang, know about the high-risk hereditary breast cancer BRCA1/2gene mutations and carrying case of Xinjiang. Explore the different genetic backgrounds BRCA1/2mutations situation; explore the relationship between BRCA1/2gene mutation and clinicopathological characteristics.(2) Through the BRCA gene sequencing results of74cases of negative high-risk hereditary breast cancer detection fresh frozen tissue BRCA1/2gene promoter methylation status, to understand hereditary breast cancer BRCA1/2promoter methylation; to explore the links between relay BRCA112promoter methylation and clinicopathological features.(3)To understand the impact of Xinjiang,82cases of high-risk BRCA hereditary breast cancer gene BRCA gene mutations and unmutated survival situations factors; understand the impact of74cases of high risk for hereditary breast cancer BRCA1/2gene promoter hypermethylation and those with unmethylated survival factors.Methods:(1) taking the82cases from Xinjiang region who take high-risk hereditary breast cancer patients as the study objectives by peripheral blood genomic DNA, all the BRCA1/2gene coding sequences were amplified. BRCA1/2gene mutation analysis is conducted by pre-screening through the denaturing high-performance liquid chromatography (DHPLC).At last it is confirmed by DNA sequencing. Application SPSS16.0statistical package was used for statistical analysis. The chi-square test was used for counting data. Sum test by rank was used for Level data. P<0.05was considered statistically significant. So as to Compare BRCA1/2gene mutation and clinic pathological characteristics between the two groups.(2)Genome DNA was extracted from the liquid nitrogen refrigeration. Sample DNA was modified with sodium bisulfate, taking the modified sample DNA as a template, respectively, adopting non-methylamine-specific primer and methylamine-specific primers for PCR amplification. A PCR product was observed in2%agars gel electrophoresis. Using statistical software SPSS16.0the chi-square test to compare the group of BRCA1and BRCA2methylamine between groups detection rate; two groups were compared using chi-square test between the clinical and pathological features.(3) collection of clinical and pathological data (age, genetic background, tumor size, axillary lymph node metastasis, molecular subtype, tumor cell grade, clinical stage, BRCA mutation, BRCA methylation status, survival time), the applying COX regression model to analyze multiple variables affecting survival time.Results:(1)82cases of high risk of hereditary breast cancer, were found in eight cases of BRCA mutations (8/82,9.76%), of which4cases of BRCA1mutations, BRCA2mutations in four cases;4cases of BRCA mutations (2073delA frame shift mutation, W372X no nonsense mutations,6873delCTCC frame shift mutations,9481delA frame shift mutations), have not been reported in the BIC database. Another four cases of mutation (Q759X nonsense mutation, IVS16+1G> A splice mutation, K467X nonsense mutations,3036delA frame shift mutations) are visible in the BIC database reports.5cases of BRCA gene mutation occurs in the1lth exon (5/8,62.5%), five cases of frame shift mutations, three cases of nonsense mutations;4patients with a family history. In triple negative breast cancer BRCA gene mutation, five cases of pathogenic mutations in BRCA genes (5/30,16.7%) were found; among BRCA1mutation rate (4/30,13.3%). Triple negative breast cancer BRCA mutation carriers compared with non-mutation, mutation early clinical staging (P=0.04), the prognosis is good.(2) In this study, all74cases were negative for BRCA gene mutations24cases were found of BRCA1/2gene promoter methylation, methylation rate is33.78%(24/74); breast cancer BRCA1gene promoter District CpG island methylation was found positive in19cases, methylation was25.67%(19/74). Found that breast cancer BRCA2gene promoter region CpG island methylation positive in5cases, methylation was6.76%(5/74). BRCA1and BRCA2positive rate of methylation rate was statistically significant difference between (P=0.002); BRCA gene promoter methylated group and unmethylated group clinic pathological characteristics in age, ethnicity, tumor size, axillaries lymph node status, clinical stage, tumor grade and molecular typing no statistically significant differences (P>0.05, in terms of molecular typing difference was statistically significant (P=0.003), triple negative breast cancer BRCA gene promoter methylation rate is40%(10/25) relatively high.(3)82cases of hereditary breast cancer survival influential factor is the clinical stage and tumor molecular typing, both of which are risky factors. After adjusting clinical staging, molecular typing of Her-2over expression hereditary breast cancer mortality risk will increase to13.195times, increased by12.195times; adjust molecular typing, the clinical staging for each additional one, hereditary breast cancer mortality risk will increase to25.924times, increased by24.924times. BRCA gene BRCA gene mutations in patients with decreased survival compared with unmutated group, survival time is shortened.clinical stage and tumor molecular typing are the two factors influencing the Negative for mutations in74cases of hereditary breast cancer survival. After adjusting clinical staging, molecular typing of Her-2over expression hereditary breast cancer mortality risk will increase to14.431times, increased by13.431times; adjust molecular typing, the clinical staging for each additional one, hereditary breast cancer mortality risk will increase to24.824times, increased by23.824times. BRCA1gene promoter methylamine in patients with better survival than BRCA1gene promoter unmethylated patients; BRCA2gene promoter methylation in patient survival than BRCA2gene promoter unmethylated patients; BRCA1/2gene promoter methylation patient survival40months ago than BRCA1/2gene promoter unmethylated patients, but survival is less than40months after the BRCA1/2gene promoter unmethylated patients; Conclusions:(1) in the multi-ethnic region of Xinjiang BRCA gene mutations may be different from elsewhere in the country; high-risky triple negative breast cancer BRCA1gene mutation rate is higher, so high-risk patients with triple negative breast cancer BRCA genetic testing should be carried out; high risk three negative breast cancer BRCA mutation carriers compared to those with no mutation, possibly in clinic pathological features and prognosis differences exist, consideration should be given for individual treatment.(2) In Xinjiang high risk of hereditary breast cancer BRCA1gene promoter methylamine rate is high; among the four kinds of breast cancer molecular subtypes of triple-negative breast cancer BRCA gene promoter methylamine rate is high.(3) Hereditary breast cancer molecular subtypes of Her-2over expression in patients are with poor prognosis; hereditary breast cancer clinical stage of patients are with poor prognosis; early diagnosis of hereditary breast cancer can prolong survival after surgery; BRCA1promoter hypermethylation and BRCA2promoter hypermethylation hereditary breast cancer survival rates were differently affected.