中国BRCA1和BRCA2基因胚系突变乳腺癌的临床病理特征比较

  目的   比较中国人群中BRCA1和BRCA2基因两种突变状态的乳腺癌患者临床病理特征的差异。   方法   收集2003年10月至2015年5月北京大学肿瘤医院收治的8 627例连续的、未经家族史和年龄选择的原发性乳腺癌患者资料,经过基因测序共有521例患者携带BRCA1/2基因致病性胚系突变,其中BRCA1突变患者203例,BRCA2突变患者318例。对这些突变患者的临床病理参数进行回顾性分析。   结果   乳腺癌患者中BRCA2基因突变频率（3.7%）高于BRCA1（2.4%）。BRCA1突变者乳腺癌发病年龄比BRCA2突变者早（中位发病年龄:43.0岁 vs. 47.0岁,P<0.01）。BRCA1突变乳腺癌患者组织学分级Ⅲ级比例显著高于BRCA2突变患者（36.2% vs. 18.4%,P<0.01）,三阴性乳腺癌（ER-/PR-/HER2-）比例也显著高于BRCA2突变者（59.2% vs. 15.4%,P<0.01）。BRCA2突变患者的腋窝淋巴结阳性比例高于BRCA1突变患者（41.8% vs. 29.6%,P<0.01）。   结论   中国BRCA1和BRCA2胚系突变乳腺癌的临床病理特征存在一定差异,提示BRCA1和BRCA2胚系突变对乳腺癌生物学行为的影响可能不同,为BRCA1和BRCA2胚系突变乳腺癌更加精准的临床管理提供依据。       

乳腺癌易感基因BRCA1和BRCA2的突变检测及其临床意义

乳腺癌易感基因BRCA1、BRCA2在家族性和遗传性乳腺癌中突变率较高。现就其功能、检测及临床应用方面的研究进展作一综述。     

219例中国汉族遗传性乳腺癌患者BRCA1和BRCA2突变的研究

  目的  分析中国新疆多民族地区的高风险遗传性乳腺癌BRCA1/2基因突变位点情况。  方法  以2009年1月到2010年12月新疆医科大学附属肿瘤医院收治的来自新疆地区的68例符合高风险遗传性乳腺癌标准的患者为研究对象,其中HBC 12例,HBOC 4例,E-BC 25例,BI-BC 10例,TNB 17例。通过外周静脉血提取基因组DNA,对BRCA1/2基因的全部编码序列进行扩增。用高效液相色谱分析（DHPLC）进行突变分析预筛,结果经DNA测序验证。  结果  BRCA1/2致病性突变在新疆地区高风险遗传性乳腺癌的突变率为8.8%（6/68）。其中BRCA1的突变率为4.4%（3/68）,BRCA2的突变率为4.4%（3/68）。不同民族之间BRCA1/2突变率无统计学差异。  结论  中国新疆多民族地区的高风险遗传性乳腺癌患者部分病例具有与内地汉族人群不同的BRCA基因突变谱。BRCA1 2073delA,BRCA2 6873del CTCC及BRCA2 9481del A可能是新疆遗传性乳腺癌特有的突变位点。     

乳腺癌组织BRCA1,BRCA1基因区域杂合性缺失的研究

目的 研究乳腺癌组织ＢＲＣＡ１、ＢＲＣＡ２基因区域的杂合性缺失（ＬＯＨ）情况。方法 采用聚合酶链式反应（ＰＣＲ）和聚丙烯酰胺凝胶电泳,对３０例散发性乳腺癌和２例姐妹乳腺癌进行ＬＯＨ的检测,同时还采用Ｇ显带法对姐妹乳腺癌患者的外周血淋巴细胞染色体畸变情况进行分析。结果 在散发性乳腺癌中,ＢＲＣＡ１、ＢＲＣＡ２基因区域的杂合性缺失率分别为６．１２％和５．７７％;姐妹二人乳腺癌组织在ＢＲＣＡ２基因区域的     

乳腺癌与BRCA

ＢＲＣＡ１和ＢＲＣＡ２基因的发现为乳腺癌的早期诊断和治疗及提高生存率和生存质量带来了希望。其在乳腺癌中有较高的突变率和特异性。本文综述乳腺癌的基因筛查及与ＢＲＣＡ之间的关系。     

68例中国新疆多民族地区遗传性乳腺癌患者BRCA1和BRCA2突变研究

  目的  分析中国新疆多民族地区的高风险遗传性乳腺癌BRCA1/2基因突变位点情况。  方法  以2009年1月到2010年12月新疆医科大学附属肿瘤医院收治的来自新疆地区的68例符合高风险遗传性乳腺癌标准的患者为研究对象,其中HBC 12例,HBOC 4例,E-BC 25例,BI-BC 10例,TNB 17例。通过外周静脉血提取基因组DNA,对BRCA1/2基因的全部编码序列进行扩增。用高效液相色谱分析（DHPLC）进行突变分析预筛,结果经DNA测序验证。  结果  BRCA1/2致病性突变在新疆地区高风险遗传性乳腺癌的突变率为8.8%（6/68）。其中BRCA1的突变率为4.4%（3/68）,BRCA2的突变率为4.4%（3/68）。不同民族之间BRCA1/2突变率无统计学差异。  结论  中国新疆多民族地区的高风险遗传性乳腺癌患者部分病例具有与内地汉族人群不同的BRCA基因突变谱。BRCA1 2073delA,BRCA2 6873del CTCC及BRCA2 9481del A可能是新疆遗传性乳腺癌特有的突变位点。      

华东地区乳腺癌散发病例BRCA1、BRCA2基因突变

目的：探讨华东地区乳腺癌散发病例BRCA1及BRCA2基因突变情况。方法：应用PCR-SSCP-Sequencing方法,对复旦大学附属肿瘤医院79例随机乳腺癌患者的癌组织及癌旁正常乳腺组织的标本进行BRCA1和BRCA2部分基因的突变检测,共6个外显子（BRCA1中的第2、11、22外显子,BRCA2中的第9,14,22外显子）23对引物。结果：发现在BRCA1和cDNA 2430碱基处存在一个T→C的单个碱基的变化,应用RFLP方法在人群中证实为一单核苷酸多态。此SNP的分布在病例及对照中等位基因频率存在差异,但并未达到显著性水平。结论：提示华东地区人群的乳腺癌群体中的BRCA1及BRCA2的突变十分罕见。     

乳腺癌BRCA1/2基因大片段重排的研究进展北大核心CSCD

乳腺癌是女性最常见的恶性肿瘤,BRCA1与BRCA2是乳腺癌最重要的易感基因,携带BRCA1/2胚系突变的女性,其乳腺癌的终身患病风险显著增高。BRCA1/2致病性突变多为单个或数个碱基改变引起的移码突变和无义突变,但常规的Sanger测序筛查方法尚不足以发现BRCA1/2其他胚系缺陷类型,如大片段重排。随着基因检测方法的进步,多种BRCA1/2基因重排被发现,在遗传性乳腺癌家族接受常规BRCA1/2基因测序未发现突变的情况下,应认真考虑检测大片段重排,以免漏诊。     

353例遗传性高危乳腺癌患者BRCA1、BRCA2、PALB2基因胚系突变的分布情况研究

[目的]通过对女性乳腺癌患者进行胚系基因检测,评估BRCA1、BRCA2、PALB2基因胚系致病/可能致病性突变在高危乳腺癌患者中的分布情况。[方法]收集2016年12月1日至2022年4月30日中山大学附属第一医院收治的女性乳腺癌患者,对已进行胚系多基因检测的353例具有遗传性高危因素的女性乳腺癌患者,对她们的检测结果进行分析,评估BRCA1、BRCA2和PALB2基因胚系致病/可能致病性突变患者的病理和临床特征等情况。[结果] 353例患者中,胚系BRCA1、BRCA2和PALB2致病/可能致病突变者共59例,突变率为16.71%,年轻患者较其他年龄患者的BRCA1突变率更高（P=0.039）,相比其他分子分型,三阴性乳腺癌患者的BRCA1突变（P<0.001）和3个基因的总突变率（P=0.007）都明显更高。和没有肿瘤家族史的患者相比,有肿瘤家族史的患者并没有体现出明显的高突变率。具有2个或2个以上危险因素的患者的基因突变率要明显高于只有1个高危因素的患者（P=0.048）。[结论] PALB2基因胚系致病/可能致病突变在高危乳腺癌患者中的发生比例较高,其重要性并不亚于BR...     

中国汉族人群中BRCA1和BRCA2基因突变携带者患乳腺癌风险的研究

背景与目的：BRCA1和BRCA2基因突变携带者终生患乳腺癌和卵巢癌的风险显著增高。通过遗传咨询,突变携带者可采取适当的措施来降低相应肿瘤的发生风险。目前,相关的报道几乎均为白种人,尚缺乏中国人群的资料。该研究旨在探索中国汉族人群中BRCA1和BRCA2基因突变携带者患乳腺癌的风险。方法：回顾20个经基因检测证实携带BRCA1或BRCA2致病性基因突变的汉族乳腺癌高风险家系。利用Kaplan-Meier生存分析法对女性BRCA1/2基因突变携带者单侧乳腺癌及对侧乳腺癌的累积发病风险进行估算。结果：BRCA1和BRCA2基因突变携带者70岁时单侧乳腺癌的累积发病风险(外显率)分别为67.2%(sx 0.100)和76.8%(sx 0.079)。与BRCA1不同的是,BRCA2基因突变携带者70岁后乳腺癌累积发病率继续增加,到80岁时达93.1%。BRCA1/2基因突变携带者对侧乳腺癌10年和20年的累积发病率分别为19.4%(sx 0.089)和50.3%(sx 0.155)。结论：中国汉族人群中BRCA1和BRCA2基因突变携带者具有很高的乳腺癌发病风险。因而对中国高风险人群进行BRCA1/2基因突变检测具有重要临床意义。     

miRNA expression patterns in normal breast tissue and invasive breast cancers of BRCA1 and BRCA2 germ-line mutation carriers

miRNA deregulation has been found to promote carcinogenesis. Little is known about miRNA deregulation in hereditary breast tumors as no miRNA expression profiling studies have been performed in normal breast tissue of BRCA1 and BRCA2 mutation carriers. miRNA profiles of 17 BRCA1- and 9 BRCA2-associated breast carcinomas were analyzed using microarrays. Normal breast tissues from BRCA1 and BRCA2 mutation carriers (both n = 5) and non-mutation carriers (n = 10) were also included. Candidate miRNAs were validated by qRT-PCR. Breast carcinomas showed extensive miRNA alteration compared to normal breast tissues in BRCA1 and BRCA2 mutation carriers. Moreover, normal breast tissue from BRCA1 mutation carriers already showed miRNA alterations compared to non-mutation carriers. Chromosomal distribution analysis showed several hotspots containing down- or up-regulated miRNAs. Pathway analysis yielded many similarities between the BRCA1 and BRCA2 axes with miRNAs involved in cell cycle regulation, proliferation and apoptosis. Lesser known pathways were also affected, including cellular movement and protein trafficking. This study provides a comprehensive insight into the potential role of miRNA deregulation in BRCA1/2-associated breast carcinogenesis. The observed extensive miRNA deregulation is likely the result of genome-wide effects of chromosomal instability caused by impaired BRCA1 or BRCA2 function. This study''s results also suggest the existence of common pathways driving breast carcinogenesis in both BRCA1 and BRCA2 germ-line mutation carriers.     

Novel BRCA1 and BRCA2 germline mutations and assessment of mutation spectrum and prevalence in Italian breast and/or ovarian cancer families

Familial aggregations of breast/ovarian cancer cases frequently depend on BRCA1/2 pathogenic mutations. Here we counselled 120 Italian breast/ovarian cancer families and selected 73 probands for BRCA1/2 mutation screening. Through this analysis we defined the prevalence of BRCA1/2 pathogenic mutations occurring in Italian breast/ovarian cancer families, enlarged the spectrum of Italian BRCA1/2 mutations by 15% and report on the identification of 13 novel variants, including two deleterious truncating mutations and two potentially pathogenic missense mutations, on the BRCA1 and BRCA2 genes. Finally in hereditary breast cancer families with three or more female breast cancer cases we observed a low mutation prevalence and a significant association with BRCA2 mutations.     

BRCA1/2 mutation analysis in male breast cancer families from North West England

64 families with a history of male breast cancer aged 60 or less or with a family history of male and female breast cancer were screened for the presence of BRCA1 and BRCA2 mutations. Seventeen pathogenic BRCA2 and four BRCA1 mutations were identified (34%) in samples from an affected family member. All but one of the mutations segregated with disease where samples were available and pedigree structure permitted. Despite high sensitivity of mutation testing only 64% of families fulfilling BCLC criteria had an identifiable pathogenic mutation. It is possible that at least some of these families may have mutations in other genes, although we found no involvement of CHEK2 1100delC.     

Predictors of contralateral breast cancer in BRCA1 and BRCA2 mutation carriers

Purpose:

The objective of this study was to estimate the risk of contralateral breast cancer in BRCA1 and BRCA2 carriers; and measure the extent to which host, family history, and cancer treatment-related factors modify the risk.

Patients and methods:

Patients were 810 women, with stage I or II breast cancer, for whom a BRCA1 or BRCA2 mutation had been identified in the family. Patients were followed from the initial diagnosis of cancer until contralateral mastectomy, contralateral breast cancer, death, or last follow-up.

Results:

Overall, 149 subjects (18.4%) developed a contralateral breast cancer. The 15-year actuarial risk of contralateral breast cancer was 36.1% for women with a BRCA1 mutation and was 28.5% for women with a BRCA2 mutation. Women younger than 50 years of age at the time of breast cancer diagnosis were significantly more likely to develop a contralateral breast cancer at 15 years, compared with those older than 50 years (37.6 vs 16.8% P=0.003). Women aged <50 years with two or more first-degree relatives with early-onset breast cancer were at high risk of contralateral breast cancer, compared with women with fewer, or no first-degree relatives with breast cancer (50 vs 36% P=0.005). The risk of contralateral breast cancer was reduced with oophorectomy (RR 0.47; 95% CI 0.30–0.76; P=0.002).

Conclusion:

The risk of contralateral breast cancer risk in BRCA mutation carriers declines with the age of diagnosis and increases with the number of first-degree relatives affected with breast cancer. Oophorectomy reduces the risk of contralateral breast cancer in young women with a BRCA mutation.     

Survival of breast cancer patients in BRCA1, BRCA2, and non-BRCA1/2 breast cancer families: a relative survival analysis from Finland.

Reports on the prognosis of familial breast cancer patients have been contradictory. True differences in survival, if they exist, would have important implications for genetic counselling and in treatment of hereditary breast cancer. We assessed the survival rates of 359 familial breast cancer patients (32 patients from BRCA1-positive families, 43 patients from BRCA2-positive families and 284 patients from BRCA1/2-negative breast cancer families) and compared them with those of all other breast cancer patients diagnosed in Finland from 1953 to 1995 (n = 59,517). Cumulative relative survival rates (RSR) were calculated by dividing the observed survival rates by the expected ones. The expected survival rates were derived from the sex, age and calendar year specific life-tables of the general population in Finland. Regression model was used to calculate relative excess risk of death (RR) and to adjust for confounding factors. The overall 5-year RSR of the patients in the BRCA1 families, BRCA2 families, non-BRCA1/2 families and among sporadic cases was 67%, 77%, 86% and 78%, respectively. However, we found no significant differences in the RR adjusted for age, stage and year of diagnosis between the different familial patient groups or the general breast cancer population. In the BRCA1 families the RR tended to be higher [RR 1.30, 95% confidence interval (CI) 0.63--2.70] and in the BRCA2 families lower (RR 0.78, 95% CI 0.39--1.57) than among the general breast cancer patient population. The RR among patients in the non-BRCA1/2 families did not differ from that of the general patient population.     

Risk-reducing salpingo-oophorectomy and breast cancer risk in BRCA1 or BRCA2 mutation carriers: A systematic review and meta-analysis

AimBRCA mutation carriers have a high lifetime risk of developing breast cancer (BC) and ovarian cancer (OC). Risk-reducing salpingo-oophorectomy (RRSO) has been shown to reduce OC risk. This meta-analysis was aim to analyze the effect of RRSO on the BC risk among BRCA1/2 mutation carriers.MethodsEmbase, PubMed, Web of Science, and Cochrane databases were searched for all studies investigating the effect of RRSO on BC risk. The pooled results were used to evaluate the association between RRSO and BC risk.ResultsThis meta-analysis included 13,965 BRCA1 and 7,057 BRCA2 mutation carriers from 14 observational studies. The pooled results showed that RRSO lowered BC risk among BRCA1 mutation carriers [hazard ratio (HR) = 0.63, 95% confidence interval (CI): 0.49–0.81, P < 0.01] and BRCA2 mutation carriers (HR = 0.51, 95% CI: 0.34–0.75, P < 0.01). RRSO reduced BC risk in younger women with BRCA1 mutation (HR = 0.48, 95% CI: 0.30–0.77, P < 0.01) and BRCA2 mutation (HR = 0.22, 95% CI: 0.08–0.65, P < 0.01). Analysis of the efficacy of RRSO at different time intervals after surgery showed a reduction of BC risk at <5 years after surgery in BRCA1 mutation carriers (HR = 0.60, 95% CI: 0.40–0.89, P = 0.01) and BRCA2 mutation carriers (HR = 0.42, 95% CI: 0.20–0.86, P = 0.02).ConclusionsRRSO is an effective way to reduce BC risk among women with BRCA1/2 mutation, especially in younger women. BRCA1/2 mutation carriers could benefit from RRSO in the immediate 5 years after surgery.     

Prevalence of BRCA1 and BRCA2 mutations in breast cancer patients from Cuba

The contribution of BRCA1 and BRCA2 to breast cancer incidence in Cuba has not yet been explored. In order to estimate the proportion of breast cancers due to BRCA1 and BRCA2 mutations in Cuba, and to identify possible Cuban founder mutations, we conducted a study of unselected breast cancer patients from Havana, Cuba. We enrolled 336 women with breast cancer from a large public hospital in the city. A family history of cancer was obtained from each patient and a blood sample was processed for DNA analysis. Mutations in BRCA1 and BRCA2 were sought using a combination of techniques, but all mutations were confirmed by direct sequencing. We were able to successfully complete testing on samples from 307 women. Among these, eight mutations were identified (seven in BRCA2 and one in BRCA1) representing 2.6% of the total, including 10% of familial cases and 10% of cases under age forty. One BRCA2 mutation (c.3394C > T) was found in two women, but no clear example of a founder mutation was identified. In summary, BRCA1 and BRCA2 mutations are not uncommon in Cuban women with breast cancer, but the absence of founder mutations precludes the development of a rapid and inexpensive clinical screening test.     

Models for predicting BRCA1 and BRCA2 mutations in Han Chinese familial breast and/or ovarian cancer patients

Purpose Our aim was to find an appropriate method to estimate the likelihood that a family history of cancer was a result of a mutation in the BRCA1 or BRCA2 genes. We also compared the performance of the established method with three different methods (Couch, Sh-E and BRCApro) to identify an alternative strategy for genetic council targeted to the specified population. Patients and methods The family history as well as individual information of two hundred unrelated probands who had completed BRCA1 and BRCA2 mutation screening was analyzed to assess the likelihood of a pathogenic mutation. A model was developed by empirical method. The performance of this model was validated in a separate patient cohort compared with BRCApro. Results Several factors were associated with mutations in univariate analysis and a logistic model was devised to estimate the probability for a proband of harboring a mutation in BRCA1 and/or BRCA2. Using a greater than 10% probability threshold, the highest accuracy was achieved by the established model when compared to other three models, presenting the highest sensitivity, PPV, NPV and area under ROC curve. The empirical model showed a better ROC curve compared to BRCApro in the verification cohort. Conclusion A probability model targeted to Han Chinese population should be a useful tool in the genetic counseling for the specified ethnic. Its ability to predict BRCA2 mutation carriers needs to be improved. Nan-Yan Rao and Zhen Hu are contributed equally to this work.