Breast Cancer Families (breast + cancer_family)

Distribution by Scientific Domains

Selected Abstracts

Histopathological features of breast cancer in carriers of ATM gene variants

R L Balleine
Aims:, Germline variants in the ataxia telangiectasia mutated (ATM) gene have been implicated in increased breast cancer risk. The aim of this study was to determine whether the histopathology of breast cancers occurring in ATM variant carriers is distinctive or resembles the described BRCA1 mutation-associated phenotype. Methods:, The histopathological features of breast cancers occurring in ATM variant carriers from multiple-case breast cancer families were compared with matched controls. The test group included 21 cases of in situ and/or invasive cancer from carriers of either the IVS10-6T,G, 2424V,G or 1420L,F ATM variants in the absence of BRCA1 or BRCA2 mutations. An additional four invasive cancers from carriers of a pathogenic BRCA1 mutation in the context of a familial ATM variant were also examined. Results:, The histopathology of breast cancers in ATM variant-only carriers was not significantly different from controls and known features of BRCA1 mutation-associated cancer were rarely seen. In contrast, these features were prominent in the small group of cases with a pathogenic BRCA1 mutation. Conclusions:, Breast cancer occurring in carriers of ATM variants is not associated with distinctive histopathological features and does not resemble the tumour phenotype commonly observed in BRCA1 mutation carriers. [source]

BRCA2 gene mutations in Greek patients with familial breast cancer ,,

HUMAN MUTATION, Issue 1 2002
Athanasios Armakolas
Abstract Family history is a well-recognized risk factor for the development of breast cancer. The isolation of BRCA1 and BRCA2 genes, the two major predisposing genes in familial and to early onset breast and ovarian cancer, has resulted to the identification of a large number of families with mutations in these two genes. Despite the large number of distinct mutations detected in both genes, several mutations have been found to recur in unrelated families of diverse geographical origin. We have analyzed 27 Greek patients with familial breast cancer the majority of those having one first and one second degree relatives affected and 28 patients with sporadic breast cancer for BRCA2 germline mutations. The techniques used were single-strand conformation polymorphism analysis (SSCP) followed by sequencing. Furthermore, the clinical presentation and prognosis of BRCA2 associated breast cancer cases was compared to 20 adequately matched for age and date of diagnosis (within one year) sporadic breast cancer patients. We identified three novel BRCA2 mutations (3058delA, 6024delTA, and 4147delG) in the ovarian cancer cluster region (OCCR) and one already known (2024del5) germline BRCA2 gene mutation in five different breast cancer families. The 4147delG mutation was detected in two unrelated patients. BRCA2 germline mutations were correlated with early-onset breast cancer RR=4.77 (95% CI: 0.666-34.463). Although patients with BRCA2 germline mutations did not have a distinct histological phenotype they had an improved overall survival (100% vs 65%). Our findings suggest that there is a cluster of novel mutations in exons 10 and 11 in Greek patients with familial breast cancer. These mutations appear to have a milder clinical phenotype when compared to the rest of the study group. © 2001 Wiley-Liss, Inc. [source]

A high proportion of founder BRCA1 mutations in Polish breast cancer families

Bohdan Górski
Abstract Three mutations in BRCA1 (5382insC, C61G and 4153delA) are common in Poland and account for the majority of mutations identified to date in Polish breast and breast,ovarian cancer families. It is not known, however, to what extent these 3 founder mutations account for all of the BRCA mutations distributed throughout the country. This question has important implications for health policy and the design of epidemiologic studies. To establish the relative contributions of founder and nonfounder BRCA mutations, we established the entire spectrum of BRCA1 and BRCA2 mutations in a large set of breast,ovarian cancer families with origins in all regions of Poland. We sequenced the entire coding regions of the BRCA1 and BRCA2 genes in 100 Polish families with 3 or more cases of breast cancer and in 100 families with cases of both breast and ovarian cancer. A mutation in BRCA1 or BRCA2 was detected in 66% of breast cancer families and in 63% of breast,ovarian cancer families. Of 129 mutations, 122 (94.6%) were in BRCA1 and 7 (5.4%) were in BRCA2. Of the 122 families with BRCA1 mutations, 119 (97.5%) had a recurrent mutation (i.e., one that was seen in at least 2 families). In particular, 111 families (91.0%) carried one of the 3 common founder mutations. The mutation spectrum was not different between families with and without ovarian cancer. These findings suggest that a rapid and inexpensive assay directed at identifying the 3 common founder mutations will have a sensitivity of 86% compared to a much more costly and labor-intensive full-sequence analysis of both genes. This rapid test will facilitate large-scale national epidemiologic and clinical studies of hereditary breast cancer, potentially including studies of chemoprevention. © 2004 Wiley-Liss, Inc. [source]

The contribution of founder mutations to early-onset breast cancer in French-Canadian women

P Ghadirian
In an ethnically-homogeneous population, it is valuable to identify founder mutations in cancer-predisposing genes. Founder mutations have been found in four breast-cancer-predisposing genes in French-Canadian breast cancer families. The frequencies of the mutant alleles have been measured neither in a large series of unselected breast cancer patients from Quebec, nor in healthy controls. These estimates are necessary to measure their contribution to the hereditary burden of breast cancer in Quebec and to help develop genetic screening policies which are appropriate for the province. We studied 564 French-Canadian women with early-onset invasive breast cancer who were treated at a single Montreal hospital. Patients had been diagnosed at age 50 or less, and were ascertained between 2004 and 2008. We screened all 564 patients for nine founder mutations: four in BRCA1, three in BRCA2 and one each in PALB2 and CHEK2. We also studied 6433 DNA samples from newborn infants from the Quebec City area to estimate the frequency of the nine variant alleles in the French-Canadian population. We identified a mutation in 36 of the 564 breast cancer cases (6.4%) and in 35 of 6443 controls (0.5%). In the breast cancer patients, the majority of mutations were in BRCA2 (54%). However, in the general population (newborn infants), the majority of mutations were in CHEK2 (54%). The odds ratio for breast cancer to age 50, given a BRCA1 mutation, was 10.1 (95% CI: 3.7,28) and given a BRCA2 mutation was 29.5 (95% CI: 12.9,67). The odds ratio for breast cancer to age 50, given a CHEK2 mutation, was 3.6 (95% CI: 1.4,9.1). One-half of the women with a mutation had a first- or second-degree relative diagnosed with breast or ovarian cancer. Thus, it can be concluded that a predisposing mutation in BRCA1, BRCA2, CHEK2 or PALB2 is present in approximately 6% of French-Canadian women with early-onset breast cancer. It is reasonable to offer screening for founder mutations to all French-Canadian women with breast cancer before age 50. The frequency of these mutations in the general population (0.5%) is too low to advocate population-based screening. [source]

A deletion/insertion mutation in the BRCA2 gene in a breast cancer family: A possible role of the Alu -polyA tail in the evolution of the deletion

Tieling Wang
Patients with breast and/or ovarian cancer were screened for gross rearrangements in the BRCA2 gene by Southern hybridization, with exon 10 and a fragment of exon 11 used as probes. One breast cancer patient with a positive family history had a 6.2-kb deletion including exons 12 and 13. The deletion breakpoint in intron 11 was in the 3, polyA tail of an Alu element, where a track of ,60 adenine nucleotide residues was inserted. Expansion of the Alu -polyA tail may have resulted from polymerase slippage during replication, representing a novel mechanism in which Alu elements mediate deletion/insertion mutations. © 2001 Wiley-Liss, Inc. [source]