@article{HansmannPliushchLeubneretal.2012,
  author    = {Hansmann, Tamara and Pliushch, Galyna and Leubner, Monika and Kroll, Patricia and Endt, Daniela and Gehrig, Andrea and Preisler-Adams, Sabine and Wieacker, Peter and Haaf, Thomas},
  title     = {Constitutive promoter methylation of BRCA1 and RAD51C in patients with familial ovarian cancer and early-onset sporadic breast cancer},
  series = {Human Molecular Genetics},
  volume    = {21},
  journal   = {Human Molecular Genetics},
  number    = {21},
  doi       = {10.1093/hmg/dds308},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125673},
  pages     = {4669-4679},
  year      = {2012},
  abstract  = {Genetic defects in breast cancer (BC) susceptibility genes, most importantly BRCA1 and BRCA2, account for ∼40\% of hereditary BC and ovarian cancer (OC). Little is known about the contribution of constitutive (soma-wide) epimutations to the remaining cases. We developed bisulfite pyrosequencing assays to screen >600 affected BRCA1/BRCA2 mutation-negative patients from the German Consortium for Hereditary Breast and Ovarian Cancer for constitutive hypermethylation of ATM, BRCA1, BRCA2, RAD51C, PTEN and TP53 in blood cells. In a second step, patients with ≥6\% promoter methylation were analyzed by bisulfite plasmid sequencing to demonstrate the presence of hypermethylated alleles (epimutations), indicative of epigenetic gene silencing. Altogether we identified nine (1.4\%) patients with constitutive BRCA1 and three (0.5\%) with RAD51C hypermethylation. Epimutations were found in both sporadic cases, in particular in 2 (5.5\%) of 37 patients with early-onset BC, and familial cases, in particular 4 (10\%) of 39 patients with OC. Hypermethylation was always confined to one of the two parental alleles in a subset (12-40\%) of the analyzed cells. Because epimutations occurred in cell types from different embryonal layers, they most likely originated in single cells during early somatic development. We propose that analogous to germline genetic mutations constitutive epimutations may serve as the first hit of tumor development. Because the role of constitutive epimutations in cancer development is likely to be largely underestimated, future strategies for effective testing of susceptibility to BC and OC should include an epimutation screen.},
  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}
}