Project description:Approximately 5%-10% of breast cancers are due to genetic predisposition caused by germline mutations; the most commonly tested genes are BRCA1 and BRCA2 mutations. Some mutations are unique to one family and others are recurrent; the spectrum of BRCA1/BRCA2 mutations varies depending on the geographical origins, populations or ethnic groups. In this review, we compiled data from 11 participating Asian countries (Bangladesh, Mainland China, Hong Kong SAR, Indonesia, Japan, Korea, Malaysia, Philippines, Singapore, Thailand and Vietnam), and from ethnic Asians residing in Canada and the USA. We have additionally conducted a literature review to include other Asian countries mainly in Central and Western Asia. We present the current pathogenic mutation spectrum of BRCA1/BRCA2 genes in patients with breast cancer in various Asian populations. Understanding BRCA1/BRCA2 mutations in Asians will help provide better risk assessment and clinical management of breast cancer.
Project description:PurposeBreast cancer is the most common malignancy among women in Lebanon and in Arab countries, with 50% of cases presenting before the age of 50 years.MethodsBetween 2009 and 2012, 250 Lebanese women with breast cancer who were considered to be at high risk of carrying BRCA1 or BRCA2 mutations because of presentation at young age and/or positive family history (FH) of breast or ovarian cancer were recruited. Clinical data were analyzed statistically. Coding exons and intron-exon boundaries of BRCA1 and BRCA2 were sequenced from peripheral blood DNA. All patients were tested for BRCA1 rearrangements using multiplex ligation-dependent probe amplification (MLPA). BRCA2 MLPA was done in selected cases.ResultsOverall, 14 of 250 patients (5.6%) carried a deleterious BRCA mutation (7 BRCA1, 7 BRCA2) and 31 (12.4%) carried a variant of uncertain significance. Eight of 74 patients (10.8%) aged ≤40 years with positive FH and only 1 of 74 patients (1.4%) aged ≤40 years without FH had a mutated BRCA. Four of 75 patients (5.3%) aged 41-50 years with FH had a deleterious mutation. Only 1 of 27 patients aged >50 years at diagnosis had a BRCA mutation. All seven patients with BRCA1 mutations had grade 3 infiltrating ductal carcinoma and triple-negative breast cancer. Nine BRCA1 and 17 BRCA2 common haplotypes were observed.ConclusionPrevalence of deleterious BRCA mutations is lower than expected and does not support the hypothesis that BRCA mutations alone cause the observed high percentage of breast cancer in young women of Lebanese and Arab descent. Studies to search for other genetic mutations are recommended.
Project description:BackgroundThe aim of this study was to identify BRCA1 and BRCA2 mutations in the Estonian population. We analyzed genetic data and questionnaire from 64 early-onset (< 45 y) breast cancer patients, 47 familial cases (patients with breast or ovarian cancer and a case of these cancers in the family), and 33 predictive cases (patients without breast or ovarian cancer, with a family history of such diseases) from Estonia for mutations in the BRCA1 gene. A sub-set of familial cases and predictive cases were also analyzed for mutations in the BRCA2 gene.MethodsFor mutation detection, we used the Polymerase Chain Reaction-Single Stranded Conformation Polymorphism Heteroduplex Analysis (PCR-SSCP-HD), followed by direct DNA sequencing.ResultsWe identified three clinically important mutations in the BRCA1 gene, including seven occurrences of the c.5382insC mutation, three of c.4154delA, and one instance of c.3881_3882delGA. We also detected six polymorphisms: c.2430T>C, c.3232A>G, c.4158A>G, c.4427T>C, c.4956A>G, and c.5002T>C. Four sequence alterations were detected in introns: c.560+64delT, c.560+ [36-38delCTT, 52-63del12], c.666-58delT, and c.5396+60insGTATTCCACTCC. In the BRCA2 gene, two clinically important mutations were found: c.9610C>T and c.6631delTTAAATG. Additionally, two alterations (c.7049G>T and c.7069+80delTTAG) with unknown clinical significance were detected.ConclusionsIn our dataset, the overall frequency of clinically important BRCA1 mutations in early-onset patients, familial cases, and predictive testing was 7.6% (144 cases, 11 mutation carriers). Pathogenic mutations were identified in 4 of the 64 early-onset breast cancer cases (6.3%). In familial cases, clinically important mutations in the BRCA1 gene were found in 6 of the 47 individuals analyzed (12.8%). In predictive cases, 1 clinically important mutation was detected in 33 individuals studied (3%). The occurrence of clinically important mutations in BRCA2 in familial cases of breast cancer was 2 of the 16 individuals analyzed (12.5%).
Project description:Breast cancer is a global burden with a woman's lifetime risk of developing breast cancer at 1 in 8. Although breast cancer is a disease that affects mostly women, the lifetime risk in men is about 1 in 1000. Most cases of breast cancer are associated with somatic mutations in breast cells that are acquired during a person's lifetime. In this scenario, the mutations are not inherited and they do not cluster in families. In hereditary breast cancer, the specific genetic factors involved will determine the inherited cancer risk. Inherited mutations in the BRCA1 or BRCA2 genes have been well-described, but mutations in ATM, CDH1, CHEK2, PALB2, PTEN, STK11, and TP53 also confer breast cancer risk. Understanding the functional significance of hereditary mutations has opened new paths for breast cancer prevention and is uncovering promising treatment strategies.
Project description:BackgroundBreast cancer is the most common female malignancy and a major cause of death in middle-aged women. So far, germline mutations in the BRCA1 and BRCA2 genes in patients with early-onset breast and/or ovarian cancer have not been identified within the Iranian population.MethodsWith the collaboration of two main centres for cancer in Iran, we obtained clinical information, family history and peripheral blood from 83 women under the age of 45 with early-onset breast cancer for scanning of germline mutations in the BRCA1 and BRCA2 genes. We analysed BRCA1 exons 11 and BRCA2 exons 10 and 11 by the protein truncation test, and BRCA1 exons 2, 3, 5, 13 and 20 and BRCA2 exons 9, 17, 18 and 23 with the single-strand conformation polymorphism assay on genomic DNA amplified by polymerase chain reaction.ResultsTen sequence variants were identified: five frameshifts (putative mutations - four novel); three missense changes of unknown significance and two polymorphisms, one seen commonly in both Iranian and British populations.ConclusionsIdentification of these novel mutations suggests that any given population should develop a mutation database for its programme of breast cancer screening. The pattern of mutations seen in the BRCA genes seems not to differ from other populations studied. Early-onset breast cancer (less than 45 years) and a limited family history is sufficient to justify mutation screening with a detection rate of over 25% in this group, whereas sporadic early-onset breast cancer (detection rate less than 5%) is unlikely to be cost-effective.
Project description:Besides BRCA1 and BRCA2, several other inheritable mutations have been identified that increase ovarian cancer risk. Surgical excision of the fallopian tubes and ovaries reduces ovarian cancer risk, but for some non-BRCA hereditary ovarian cancer mutations the benefit of this intervention is unclear. The fallopian tubes of women with hereditary ovarian cancer mutations provide many insights into the early events of carcinogenesis and process of malignant transformation. Here we review cancer pathogenesis in hereditary cases of ovarian cancer, the occurrence of pre-invasive lesions and occult carcinoma in mutation carriers and their clinical management.
Project description:ObjectiveTo investigate the prevalence of BRCA1/2 gene variants and evaluate the clinical and pathological characteristics associated with these variants in Chinese Hakka breast cancer patients.MethodsA total of 409 breast cancer patients were analyzed based on next-generation sequencing results, with 337 categorized as non-carriers and 72 as carriers of BRCA1/2 variants. Data on the patients' BRCA1/2 gene mutation status, clinical and pathological characteristics, as well as menstrual and reproductive information, were collected, analyzed, compared, and tabulated. Logistic regression analysis was performed to explore the relationship between clinical characteristics and pathogenic variants.ResultsAmong the patients, 72 were identified as carriers of pathogenic or likely pathogenic variants in BRCA1/2, while 337 had likely benign or benign mutations. The BRCA1 c.2635G > T (p. Glu879*) variant was detected at a high frequency, accounting for 12.5% (4/32) of the BRCA1 mutations, while the c.5164_5165del (p.Ser1722Tyrfs*4) variant was common among the BRCA2 mutations, accounting for 17.5% (7/40). It was observed that a higher proportion of BRCA1 carriers had the triple-negative breast cancer subtype, whereas more BRCA2 carriers exhibited estrogen receptor (ER) + and progesterone receptor (PR) + subtypes. Multivariate logistic regression analysis revealed that a family history of cancer (OR = 2.36, 95% CI = 1.00-5.54), bilateral cancer (OR = 4.78, 95% CI 1.61-14.20), human epidermal growth factor receptor 2 (HER2)- (OR = 8.23, 95% CI 3.25-20.84), and Ki67 ≥ 15% (OR = 3.88, 95% CI 1.41-10.65) were associated with BRCA1/2 mutations, with the age at diagnosis, age at menarche, and premenopausal status serving as covariates.ConclusionsThe most common pathogenic variant of the BRCA1 and BRCA2 in breast cancer patients was c.2635G > T and c.5164_5165del, respectively. Additionally, a family history of cancer, bilateral cancer, HER2-, and Ki67 ≥ 15% were identified as independent predictors of BRCA1/2 pathogenic variants.
Project description:ImportanceBRCA testing is recommended for young women diagnosed as having breast cancer, but little is known about decisions surrounding testing and how results may influence treatment decisions in young patients.ObjectivesTo describe the use of BRCA testing and to evaluate how concerns about genetic risk and use of genetic information affect subsequent treatment decisions in young women with breast cancer.Design, setting, and participantsCross-sectional analysis of data collected following the opening of the study to accrual from October 10, 2006, through December 31, 2014, as part of the Helping Ourselves, Helping Others: Young Women's Breast Cancer Study, an ongoing prospective cohort study. Study participants included 897 women aged 40 years and younger at breast cancer diagnosis from 11 academic and community medical centers.Main outcomes and measuresFrequency and trends in the use of BRCA testing and how genetic information is used to make treatment decisions among women who test positive vs negative for a BRCA mutation.ResultsA total of 780 (87.0%) of 897 women reported BRCA testing by 1 year after breast cancer diagnosis (mean age at diagnosis, 35.3 vs 36.9 years for untested women; P < .001), with the frequency of testing increasing among women diagnosed from August 1, 2006, through December 31, 2013. Of 39 women who were diagnosed as having breast cancer in 2006, 30 (76.9%) reported testing. In 2007, a slightly lower percentage of women (87 of 124 [70.2%]) reported testing; however, the proportion tested increased each subsequent year, with 141 (96.6%) of 146 and 123 (95.3%) of 129 women diagnosed as having breast cancer in 2012 and 2013, respectively, reporting BRCA testing (P < .001). Among untested women, 37 (31.6%) of 117 did not report discussion of the possibility that they might have a mutation with a physician and/or genetic counselor, and 43 (36.8%) of 117 were thinking of testing in the future. A total of 248 (29.8%) of 831 women said that knowledge or concern about genetic risk influenced treatment decisions; among these women, 76 (86.4%) of 88 mutation carriers and 82 (51.2%) of 160 noncarriers chose bilateral mastectomy (P < .001). Fewer women reported that systemic treatment decisions were influenced by genetic risk concern.Conclusions and relevanceRates of BRCA1 and BRCA2 mutation testing are increasing in young women with breast cancer. Given that knowledge and concern about genetic risk influence surgical decisions and may affect systemic therapy trial eligibility, all young women with breast cancer should be counseled and offered genetic testing, consistent with the National Comprehensive Cancer Network guidelines.
Project description:Breast cancer is the most common female malignancy and the leading cancer mortality cause among Algerian women. Germline mutations in the BRCA1 and BRCA2 genes in patients with early-onset breast cancer have not been clearly identified within the Algerian population. It is necessary to study the BRCA1/2 genes involvement in the Algerian breast cancer occurrence. We performed this study to define germline mutations in BRCA1/2 and their implication in breast cancer among young women from eastern Algeria diagnosed or treated with primary invasive breast cancer at the age of 40 or less who were referred to Anti-Cancer Center of Setif, Algeria. Case series were unselected for family history. Eight distinct pathogenic mutations were identified in eight unrelated families. Three deleterious mutations and one large genomic rearrangement involving deletion of exon 2 were found in BRCA1 gene. In addition, four mutations within the BRCA2 gene and one large genomic rearrangement were identified. Novel mutation was found among Algerian population. Moreover, five variants of uncertain clinical significance and favor polymorphisms were identified. Our data suggest that BRCA1/2 mutations are responsible for a significant proportion of breast cancer in Algerian young women.
Project description:PurposeThe aim of this study is to further understand the status of BRCA1 and BRCA2 mutation among Chinese high-risk breast cancer patients in multiple-ethnic regions of China.MethodsA total of 79 blood samples of high-risk breast cancer patients from Xinjiang Uyghur autonomous region were analyzed by PCR-DHPLC sequencing analysis.ResultsAnalysis with full length of the two genes identified a total of 6 deleterious mutations (2073delA, 2394C-T [Q759X] and IVS16+1G>A in BRCA1; 1627A-T [K467X], 6873delCTCC and 9481delA in BRCA2) in this cohort. The prevalence of BRCA1/2 germline mutation was about 7.6% (6/79) in the Xinjiang multiple ethnic region of China. Among them, 3 novel deleterious mutations, 2073delA in BRCA1 (Han ethnic Chinese) and BRCA2 variants 6873delCTCC and 9481delA (both are Kazakh ethnic Chinese), were identified and they had never been reported in breast cancer information core (BIC) database before. 2394C-T (Q759X) and IVS16+1G>A, in BRCA1 and BRCA2 variants 1627A-T were previously reported in other populations but not Chinese. Among 6 of the BRCA-related tumors, three BRCA1- and one BRCA2-associated tumors were in triple negative (estrogen receptor, progesterone receptor, and HER2 negative expressed) status and exhibited a high tumor grade. So far none of these 6 deleterious mutations were reported in ethnic Han Chinese.ConclusionBRCA germline mutation in Chinese multiple ethnicity region may exhibit different genotypes compared to ethnic Han Chinese in other regions. These differences may arise from interaction of genetic background and environmental factors.