@article{SepahiFaustSturmetal.2019,
  author    = {Sepahi, Ilnaz and Faust, Ulrike and Sturm, Marc and Bosse, Kristin and Kehrer, Martin and Heinrich, Tilman and Grundman-Hauser, Kathrin and Bauer, Peter and Ossowski, Stephan and Susak, Hana and Varon, Raymonda and Schr{\"o}ck, Evelin and Niederacher, Dieter and Auber, Bernd and Sutter, Christian and Arnold, Norbert and Hahnen, Eric and Dworniczak, Bernd and Wang-Gorke, Shan and Gehrig, Andrea and Weber, Bernhard H. F. and Engel, Christoph and Lemke, Johannes R. and Hartkopf, Andreas and Huu Phuc, Nguyen and Riess, Olaf and Schroeder, Christopher},
  title     = {Investigating the effects of additional truncating variants in DNA-repair genes on breast cancer risk in BRCA1-positive women},
  series = {BMC Cancer},
  volume    = {19},
  journal   = {BMC Cancer},
  doi       = {10.1186/s12885-019-5946-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-237676},
  year      = {2019},
  abstract  = {Background Inherited pathogenic variants in BRCA1 and BRCA2 are the most common causes of hereditary breast and ovarian cancer (HBOC). The risk of developing breast cancer by age 80 in women carrying a BRCA1 pathogenic variant is 72\%. The lifetime risk varies between families and even within affected individuals of the same family. The cause of this variability is largely unknown, but it is hypothesized that additional genetic factors contribute to differences in age at onset (AAO). Here we investigated whether truncating and rare missense variants in genes of different DNA-repair pathways contribute to this phenomenon. Methods We used extreme phenotype sampling to recruit 133 BRCA1-positive patients with either early breast cancer onset, below 35 (early AAO cohort) or cancer-free by age 60 (controls). Next Generation Sequencing (NGS) was used to screen for variants in 311 genes involved in different DNA-repair pathways. Results Patients with an early AAO (73 women) had developed breast cancer at a median age of 27 years (interquartile range (IQR); 25.00-27.00 years). A total of 3703 variants were detected in all patients and 43 of those (1.2\%) were truncating variants. The truncating variants were found in 26 women of the early AAO group (35.6\%; 95\%-CI 24.7 - 47.7\%) compared to 16 women of controls (26.7\%; 95\%-CI 16.1 to 39.7\%). When adjusted for environmental factors and family history, the odds ratio indicated an increased breast cancer risk for those carrying an additional truncating DNA-repair variant to BRCA1 mutation (OR: 3.1; 95\%-CI 0.92 to 11.5; p-value = 0.07), although it did not reach the conventionally acceptable significance level of 0.05. Conclusions To our knowledge this is the first time that the combined effect of truncating variants in DNA-repair genes on AAO in patients with hereditary breast cancer is investigated. Our results indicate that co-occurring truncating variants might be associated with an earlier onset of breast cancer in BRCA1-positive patients. Larger cohorts are needed to confirm these results.},
  language  = {en}
}
@article{EngelRhiemHahnenetal.2018,
  author    = {Engel, Christoph and Rhiem, Kerstin and Hahnen, Eric and Loibl, Sibylle and Weber, Karsten E. and Seiler, Sabine and Zachariae, Silke and Hauke, Jan and Wappenschmidt, Barbara and Waha, Anke and Bl{\"u}mcke, Britta and Kiechle, Marion and Meindl, Alfons and Niederacher, Dieter and Bartram, Claus R. and Speiser, Dorothee and Schlegelberger, Brigitte and Arnold, Norbert and Wieacker, Peter and Leinert, Elena and Gehrig, Andrea and Briest, Susanne and Kast, Karin and Riess, Olaf and Emons, G{\"u}nter and Weber, Bernhard H. F. and Engel, Jutta and Schmutzler, Rita K.},
  title     = {Prevalence of pathogenic BRCA1/2 germline mutations among 802 women with unilateral triple-negative breast cancer without family cancer history},
  series = {BMC Cancer},
  volume    = {18},
  journal   = {BMC Cancer},
  organization    = {German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC)},
  doi       = {10.1186/s12885-018-4029-y},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226763},
  year      = {2018},
  abstract  = {Background There is no international consensus up to which age women with a diagnosis of triple-negative breast cancer (TNBC) and no family history of breast or ovarian cancer should be offered genetic testing for germline BRCA1 and BRCA2 (gBRCA) mutations. Here, we explored the association of age at TNBC diagnosis with the prevalence of pathogenic gBRCA mutations in this patient group. Methods The study comprised 802 women (median age 40 years, range 19-76) with oestrogen receptor, progesterone receptor, and human epidermal growth factor receptor type 2 negative breast cancers, who had no relatives with breast or ovarian cancer. All women were tested for pathogenic gBRCA mutations. Logistic regression analysis was used to explore the association between age at TNBC diagnosis and the presence of a pathogenic gBRCA mutation. Results A total of 127 women with TNBC(15.8\%) were gBRCA mutation carriers (BRCA1: n = 118, 14.7\%; BRCA2: n = 9, 1. 1\%). The mutation prevalence was 32.9\% in the age group 20-29 years compared to 6.9\% in the age group 60-69 years. Logistic regression analysis revealed a significant increase of mutation frequency with decreasing age at diagnosis (odds ratio 1.87 per 10 year decrease, 95\% CI 1.50-2.32, p < 0.001). gBRCA mutation risk was predicted to be > 10\% for women diagnosed below approximately 50 years. Conclusions Based on the general understanding that a heterozygous mutation probability of 10\% or greater justifies gBRCA mutation screening, women with TNBC diagnosed before the age of 50 years and no familial history of breast and ovarian cancer should be tested for gBRCA mutations. In Germany, this would concern approximately 880 women with newly diagnosed TNBC per year, of whom approximately 150 are expected to be identified as carriers of a pathogenic gBRCA mutation.},
  language  = {en}
}
@article{FockenSteinemannSkawranetal.2011,
  author    = {Focken, T. and Steinemann, D. and Skawran, B. and Hofmann, W. and Ahrens, P. and Arnold, N. and Kroll, P. and Kreipe, H. and Schlegelberger, B. and Gadzicki, D.},
  title     = {Human BRCA1-associated breast cancer: No increase in numerical chromosomal instability compared to sporadic tumors},
  series = {Cytogenetic and Genome Research},
  volume    = {135},
  journal   = {Cytogenetic and Genome Research},
  number    = {2},
  issn      = {1424-8581},
  doi       = {10.1159/000332005},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196770},
  pages     = {84 -- 92},
  year      = {2011},
  abstract  = {BRCA1 is a major gatekeeper of genomic stability. Acting in multiple central processes like double-strand break repair, centrosome replication, and checkpoint control, BRCA1 participates in maintaining genomic integrity and protects the cell against genomic instability. Chromosomal instability (CIN) as part of genomic instability is an inherent characteristic of most solid tumors and is also involved in breast cancer development. In this study, we determined the extent of CIN in 32 breast cancer tumors of women with a BRCA1 germline mutation compared to 62 unselected breast cancers. We applied fluorescence in situ hybridization (FISH) with centromere-specific probes for the chromosomes 1, 7, 8, 10, 17, and X and locus-specific probes for 3q27 (BCL6), 5p15.2 (D5S23), 5q31 (EGR1), 10q23.3 (PTEN), and 14q32 (IGH@) on formalin-fixed paraffin-embedded tissue microarray sections. Our hypothesis of an increased level of CIN in BRCA1-associated breast cancer could not be confirmed by this approach. Surprisingly, we detected no significant difference in the extent of CIN in BRCA1-mutated versus sporadic tumors. The only exception was the CIN value for chromosome 1. Here, the extent of CIN was slightly higher in the group of sporadic tumors.},
  language  = {en}
}
@article{VigoritoKuchenbaeckerBeesleyetal.2016,
  author    = {Vigorito, Elena and Kuchenbaecker, Karoline B. and Beesley, Jonathan and Adlard, Julian and Agnarsson, Bjarni A. and Andrulis, Irene L. and Arun, Banu K. and Barjhoux, Laure and Belotti, Muriel and Benitez, Javier and Berger, Andreas and Bojesen, Anders and Bonanni, Bernardo and Brewer, Carole and Caldes, Trinidad and Caligo, Maria A. and Campbell, Ian and Chan, Salina B. and Claes, Kathleen B. M. and Cohn, David E. and Cook, Jackie and Daly, Mary B. and Damiola, Francesca and Davidson, Rosemarie and de Pauw, Antoine and Delnatte, Capucine and Diez, Orland and Domchek, Susan M. and Dumont, Martine and Durda, Katarzyna and Dworniczak, Bernd and Easton, Douglas F. and Eccles, Diana and Ardnor, Christina Edwinsdotter and Eeles, Ros and Ejlertsen, Bent and Ellis, Steve and Evans, D. Gareth and Feliubadalo, Lidia and Fostira, Florentia and Foulkes, William D. and Friedman, Eitan and Frost, Debra and Gaddam, Pragna and Ganz, Patricia A. and Garber, Judy and Garcia-Barberan, Vanesa and Gauthier-Villars, Marion and Gehrig, Andrea and Gerdes, Anne-Marie and Giraud, Sophie and Godwin, Andrew K. and Goldgar, David E. and Hake, Christopher R. and Hansen, Thomas V. O. and Healey, Sue and Hodgson, Shirley and Hogervorst, Frans B. L. and Houdayer, Claude and Hulick, Peter J. and Imyanitov, Evgeny N. and Isaacs, Claudine and Izatt, Louise and Izquierdo, Angel and Jacobs, Lauren and Jakubowska, Anna and Janavicius, Ramunas and Jaworska-Bieniek, Katarzyna and Jensen, Uffe Birk and John, Esther M. and Vijai, Joseph and Karlan, Beth Y. and Kast, Karin and Khan, Sofia and Kwong, Ava and Laitman, Yael and Lester, Jenny and Lesueur, Fabienne and Liljegren, Annelie and Lubinski, Jan and Mai, Phuong L. and Manoukian, Siranoush and Mazoyer, Sylvie and Meindl, Alfons and Mensenkamp, Arjen R. and Montagna, Marco and Nathanson, Katherine L. and Neuhausen, Susan L. and Nevanlinna, Heli and Niederacher, Dieter and Olah, Edith and Olopade, Olufunmilayo I. and Ong, Kai-ren and Osorio, Ana and Park, Sue Kyung and Paulsson-Karlsson, Ylva and Pedersen, Inge Sokilde and Peissel, Bernard and Peterlongo, Paolo and Pfeiler, Georg and Phelan, Catherine M. and Piedmonte, Marion and Poppe, Bruce and Pujana, Miquel Angel and Radice, Paolo and Rennert, Gad and Rodriguez, Gustavo C. and Rookus, Matti A. and Ross, Eric A. and Schmutzler, Rita Katharina and Simard, Jacques and Singer, Christian F. and Slavin, Thomas P. and Soucy, Penny and Southey, Melissa and Steinemann, Doris and Stoppa-Lyonnet, Dominique and Sukiennicki, Grzegorz and Sutter, Christian and Szabo, Csilla I. and Tea, Muy-Kheng and Teixeira, Manuel R. and Teo, Soo-Hwang and Terry, Mary Beth and Thomassen, Mads and Tibiletti, Maria Grazia and Tihomirova, Laima and Tognazzo, Silvia and van Rensburg, Elizabeth J. and Varesco, Liliana and Varon-Mateeva, Raymonda and Vratimos, Athanassios and Weitzel, Jeffrey N. and McGuffog, Lesley and Kirk, Judy and Toland, Amanda Ewart and Hamann, Ute and Lindor, Noralane and Ramus, Susan J. and Greene, Mark H. and Couch, Fergus J. and Offit, Kenneth and Pharoah, Paul D. P. and Chenevix-Trench, Georgia and Antoniou, Antonis C.},
  title     = {Fine-Scale Mapping at 9p22.2 Identifies Candidate Causal Variants That Modify Ovarian Cancer Risk in BRCA1 and BRCA2 Mutation Carriers},
  series = {PLoS ONE},
  volume    = {11},
  journal   = {PLoS ONE},
  number    = {7},
  doi       = {10.1371/journal.pone.0158801},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166869},
  pages     = {e0158801},
  year      = {2016},
  abstract  = {Population-based genome wide association studies have identified a locus at 9p22.2 associated with ovarian cancer risk, which also modifies ovarian cancer risk in BRCA1 and BRCA2 mutation carriers. We conducted fine-scale mapping at 9p22.2 to identify potential causal variants in BRCA1 and BRCA2 mutation carriers. Genotype data were available for 15,252 (2,462 ovarian cancer cases) BRCA1 and 8,211 (631 ovarian cancer cases) BRCA2 mutation carriers. Following genotype imputation, ovarian cancer associations were assessed for 4,873 and 5,020 SNPs in BRCA1 and BRCA 2 mutation carriers respectively, within a retrospective cohort analytical framework. In BRCA1 mutation carriers one set of eight correlated candidate causal variants for ovarian cancer risk modification was identified (top SNP rs10124837, HR: 0.73, 95\%CI: 0.68 to 0.79, p-value 2× 10-16). These variants were located up to 20 kb upstream of BNC2. In BRCA2 mutation carriers one region, up to 45 kb upstream of BNC2, and containing 100 correlated SNPs was identified as candidate causal (top SNP rs62543585, HR: 0.69, 95\%CI: 0.59 to 0.80, p-value 1.0 × 10-6). The candidate causal in BRCA1 mutation carriers did not include the strongest associated variant at this locus in the general population. In sum, we identified a set of candidate causal variants in a region that encompasses the BNC2 transcription start site. The ovarian cancer association at 9p22.2 may be mediated by different variants in BRCA1 mutation carriers and in the general population. Thus, potentially different mechanisms may underlie ovarian cancer risk for mutation carriers and the general population.},
  language  = {en}
}
@article{GaletzkaHansmannElHajjetal.2012,
  author    = {Galetzka, Danuta and Hansmann, Tamara and El Hajj, Nady and Weis, Eva and Irmscher, Benjamin and Ludwig, Marco and Schneider-R{\"a}tzke, Brigitte and Kohlschmidt, Nicolai and Beyer, Vera and Bartsch, Oliver and Zechner, Ulrich and Spix, Claudia and Haaf, Thomas},
  title     = {Monozygotic twins discordant for constitutive BRCA1 promoter methylation, childhood cancer and secondary cancer},
  series = {Epigenetics},
  volume    = {7},
  journal   = {Epigenetics},
  number    = {1},
  doi       = {10.4161/epi.7.1.18814},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125386},
  pages     = {47-54},
  year      = {2012},
  abstract  = {We describe monozygotic twins discordant for childhood leukemia and secondary thyroid carcinoma. We used bisulfite pyrosequencing to compare the constitutive promoter methylation of BRCA1 and several other tumor suppressor genes in primary fibroblasts. The affected twin displayed an increased BRCA1 methylation (12\%), compared with her sister (3\%). Subsequent bisulfite plasmid sequencing demonstrated that 13\% (6 of 47) BRCA1 alleles were fully methylated in the affected twin, whereas her sister displayed only single CpG errors without functional implications. This between-twin methylation difference was also found in irradiated fibroblasts and untreated saliva cells. The BRCA1 epimutation may have originated by an early somatic event in the affected twin: approximately 25\% of her body cells derived from different embryonic cell lineages carry one epigenetically inactivated BRCA1 allele. This epimutation was associated with reduced basal protein levels and a higher induction of BRCA1 after DNA damage. In addition, we performed a genome-wide microarray analysis of both sisters and found several copy number variations, i.e., heterozygous deletion and reduced expression of the RSPO3 gene in the affected twin. This monozygotic twin pair represents an impressive example of epigenetic somatic mosaicism, suggesting a role for constitutive epimutations, maybe along with de novo genetic alterations in recurrent tumor development.},
  language  = {en}
}