Discussion
We employed an original phylogenetic analytic method, coupled with more classical molecular epidemiologic analyses, to detect mitochondrial haplogroups differentially enriched for affected
BRCA1/2 mutation carriers. We successfully inferred haplogroups for more than 90% of individuals in our dataset. After haplogroup imputation, the ALTree method identified T1a1 in the T clade as differentially enriched in affected
BRCA2 mutation carriers, whereas no enrichment difference was found for
BRCA1 mutation carriers. The T subclade is present in 4% of African populations compared with 11% in Caucasian and Eastern European populations [
43]. In our data, the T subclade represented 9.34% of
BRCA1 mutation carriers and 9.30% of
BRCA2 carriers. The ALTree method also identified three potential breast cancer susceptibility loci in mtDNA. The main goals of using the phylogenetic method we used were to improve statistical power by regrouping subclades according to genetic considerations, to limit the number of tests performed and to precisely quantify this number. ALTree identified three SNPs of interest. Whereas the association we observed could possibly be driven by a single SNP, no difference was observed between multivariate and univariate cox models including the three SNPs identified by ALTree (data not shown).
In this study, we investigated to what extent mtDNA variability modified breast cancer risk in individuals carrying pathogenic mutations in
BRCA1/2. A large proportion of breast cancer heritability still remains unexplained today [
44]. Different methods exist to study genomic susceptibility to a disease, such as linkage analyses (which identified the
BRCA1 and
BRCA2 susceptibility genes) or genome-wide association studies (GWASs). However, classical linkage analysis cannot be applied to the haploid mitochondrial genome. Furthermore, commercial GWAS chips available do not adequately capture the majority of mtDNA SNPs. A non-genome-wide and mtDNA-focused approach was required to explore how mtDNA variability influences breast cancer risk. Here we have shown that
BRCA2 mutation carriers with the subclade T1a1 have between 30% and 50% less risk of breast cancer than those with other clades, which, if validated, is a clinically meaningful risk reduction and may influence the choice of risk management strategies.
The association we observed among
BRCA2, but not
BRCA1, mutation carriers may reveal a functional alteration that would be specific to mechanisms involving
BRCA2-related breast cancer. Today, it is established that
BRCA1- and
BRCA2-associated breast cancers are not phenotypically identical. These two types of tumors do not harbor the same gene expression profiles or copy number alterations [
45]. Breast cancer risk modifiers in
BRCA1/2 mutation carriers have already been identified [
46]. However, most of them are specific from one or the other type of mutation carried [
47]. It is therefore not surprising that this observation is observed in
BRCA2 mutation carriers only.
Our inability to assign haplogroups to 9% of study participants could have three main explanations. First, given the high mutation rate in the mitochondrial genome, observed combinations of mtDNA SNPs might have appeared relatively recently in the general population, and the corresponding haplotypes might not yet be incorporated into PhyloTree. Second, only one genotyping error could lead to chimeric haplotypes that do not exist, although, given the quality of our genotyping data, this is unlikely. Third, the mitochondrial reference evolutionary tree PhyloTree is based on phylogeny reconstruction by parsimony, and, for some subclades, it might be suboptimal, especially for haplogroups relying on few mitochondrial sequences, as is the case for African haplogroups [
48]. In cases of uncertainty, the choice we made to assign the most recent common ancestor to the studied haplotype enabled us to improve statistical power without introducing a bias in the detected association. For the association detected between T, T1* and T2* subclades, the haplogroup inference method used did not bias the counts of affected and unaffected individuals in these subclades. More details are presented in Additional file
6. Furthermore, on the basis of the haplogroup inference with our method of 630 European and Caucasian mtDNA sequences whose haplogroup is known, we successfully assigned the correct main haplogroup and subhaplogroup of 100% of sequences belonging to T, T2* and T1a1* haplogroups.
We quantified the effect corresponding to the detected association by using a more classical approach. We built a weighted Cox regression including inferred haplogroup as an explicative variable. However, the uncertainty in haplogroup inference was not taken into account in this model. Nevertheless, based on haplogroup assignment and regrouping performed in clade T, affected and unaffected counts of individuals in this clade were not biased.
With only 129 loci genotyped over the 16,569 nucleotides composing the mitochondrial genome, we certainly did not explore the full variability of mitochondrial haplotypes. A characterization of individual mitochondrial genomes would require more complete data acquisition methods to be used, such as next-generation sequencing. However, next-generation sequencing has its own limits and challenges, because some regions of the mitochondrial genome are not easily mappable, owing to a high homology with the nuclear genome, among other factors, and important bioinformatics treatment is necessary to overcome sequencing technology biases. Finally, even for a relatively short genome of “only” 16,569 bp, mtDNA sequencing of more than 20,000 individuals would represent a major increase in cost relative to genotyping 129 SNPs.
ALTree identified T9899C, G11812A/rs41544217 and G13708A/rs28359178 as three potential susceptibility sites for the discovered association (see Additional file
7). These three SNPs are located in the coding part of genes
MT-CO3,
MT-ND4 and
MT-ND5, respectively. When looking at PhyloTree, T9899C seems to be involved in T1 subclade definition, whereas G13708A and A11812G are involved in T2 subclade definition. Whereas T98899C and G11821/rs41544217 are synonymous SNPs, G10398A leads to a change of amino acid in the final protein (from alanine to threonine). These two synonymous SNPs have never been described in a disease context in the literature. G13708A is also known for being a secondary mutation for Leber’s hereditary optic neuropathy (LHON) and multiple sclerosis [
49]. Although the role of secondary mutations in LHON is still controversial, G13708A could be associated with impairment of the respiratory chain in this pathology. G13708A has also been described as a somatic mutation in a breast cancer tumor, whereas it was not present in adjacent normal tissue or in blood leukocytes [
50]. A high proportion of mitochondrial somatic tumor-specific variants are also known mtDNA SNPs, which is consistent with the hypothesis that tumor cells are prone to acquire the same mutations that segregate into mtDNA by selective adaptation when humans migrated out of Africa and confronted new environments [
51]. Interestingly, the germline variant G13708A has already been shown to be inversely associated with familial breast cancer risk (with the same direction of the association), with a breast cancer odds ratio of 0.47 (95% CI, 0.24 to 0.92) [
52]. None of these SNPs have been described in the context of ovarian cancer.
The corrected
P-value obtained using ALTree in studying clade T is 0.02, which is not highly significant. A replication step should be performed to validate these results. However, it will be difficult to include enough women in this replication step, given the specific profile studied here. In fact, the estimations of
BRCA2 pathogenic mutations in the general population range from 0.068% [
5] to 0.69% [
53]. T1a1 represents only a small percentage of European haplogroups (from 1% to 2%). The number of women who have this association is therefore low. However, women carrying such mutations are confronted with drastic choices regarding the prevention of breast cancer, notably prophylactic mastectomy or complete hysterectomy. If breast cancer risk is really reduced by a factor of 2 for women with T1a1, this could be an important fact to take into account for breast cancer prevention.
Acknowledgements
Collaborative Oncological Gene-environment Study (COGS)
: This study would not have been possible without the contributions of the following: Per Hall (COGS); Kyriaki Michailidou, Manjeet K Bolla and Qin Wang (Breast Cancer Association Consortium (BCAC)); Rosalind A Eeles, Ali Amin Al Olama, Zsofia Kote-Jarai and Sara Benlloch (PRACTICAL); Alison M Dunning, Craig Luccarini, Michael Lush and the staff of the Centre for Cancer Genetic Epidemiology; Simard and Daniel C Tessier, Francois Bacot, Daniel Vincent, Sylvie LaBoissière and Frederic Robidoux and the staff of the McGill University and Génome Québec Innovation Centre; and Julie M Cunningham, Sharon A Windebank, Christopher A Hilker, Jeffrey Meyer and the staff of Mayo Clinic Genotyping Core Facility.
Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA)
: Maggie Angelakos, Judi Maskiell, Gillian Dite and Helen Tsimiklis; members of and participants in the New York site of the Breast Cancer Family Registry; members of and participants in the Ontario Familial Breast Cancer Registry for their contributions to the study; Vilius Rudaitis, Laimonas Griškevičius, Drs Janis Eglitis, Anna Krilova and Aivars Stengrevics; the families who contribute to the BRCA-gene mutations and breast cancer in South African women (BMBSA) study; Chun Ding and Linda Steele; Alicia Barroso, Rosario Alonso, Guillermo Pita, Alessandra Viel and Lara della Puppa of the Centro di Riferimento Oncologico, IRCCS, Aviano (PN), Italy; Laura Papi of the University of Florence, Florence, Italy; Monica Barile of the Istituto Europeo di Oncologia, Milan, Italy; Liliana Varesco of the IRCCS AOU San Martino – IST Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy; Stefania Tommasi, Brunella Pilato and Rossana Lambo of the Istituto Nazionale Tumori “Giovanni Paolo II” – Bari, Italy; Aline Martayan of the Istituto Nazionale Tumori Regina Elena, Rome, Italy; Maria Grazia Tibiletti of the Ospedale di Circolo-Università dell’Insubria, Varese, Italy; and the personnel of the Cogentech Cancer Genetic Test Laboratory, Milan, Italy.
Epidemiological Study of BRCA1 and BRCA2 Mutation Carriers (EMBRACE) Collaborating Centers
: coordinating center, Cambridge, UK: Debra Frost, Steve Ellis, Elena Fineberg and Radka Platte; North of Scotland Regional Genetics Service, Aberdeen, UK: Zosia Miedzybrodzka and Helen Gregory; Northern Ireland Regional Genetics Service, Belfast, UK: Patrick Morrison and Lisa Jeffers; West Midlands Regional Clinical Genetics Service, Birmingham, UK: Trevor Cole, Kai-ren Ong and Jonathan Hoffman; South West Regional Genetics Service, Bristol, UK: Alan Donaldson and Margaret James; East Anglian Regional Genetics Service, Cambridge, UK: Marc Tischkowitz, Joan Paterson and Amy Taylor; Medical Genetics Services for Wales, Cardiff, UK: Alexandra Murray, Mark T Rogers and Emma McCann; St James’s Hospital, Dublin, and National Centre for Medical Genetics, Dublin, Ireland: M John Kennedy and David Barton; South East of Scotland Regional Genetics Service, Edinburgh, UK: Mary Porteous and Sarah Drummond; Peninsula Clinical Genetics Service, Exeter, UK: Carole Brewer, Emma Kivuva, Anne Searle, Selina Goodman and Kathryn Hill; West of Scotland Regional Genetics Service, Glasgow, UK: Rosemarie Davidson, Victoria Murday, Nicola Bradshaw, Lesley Snadden, Mark Longmuir, Catherine Watt, Sarah Gibson, Eshika Haque, Ed Tobias and Alexis Duncan; South East Thames Regional Genetics Service, Guy’s Hospital London: Louise Izatt, Chris Jacobs and Caroline Langman; North West Thames Regional Genetics Service, Harrow, UK: Huw Dorkins; Leicestershire Clinical Genetics Service, Leicester, UK: Julian Barwell; Yorkshire Regional Genetics Service, Leeds, UK: Julian Adlard and Gemma Serra-Feliu; Cheshire & Merseyside Clinical Genetics Service, Liverpool, UK: Ian Ellis and Catherine Houghton; Manchester Regional Genetics Service, Manchester, UK: D Gareth Evans, Fiona Lalloo and Jane Taylor. North East Thames Regional Genetics Service, NE Thames, London: Lucy Side, Alison Male and Cheryl Berlin; Nottingham Centre for Medical Genetics, Nottingham, UK: Jacqueline Eason and Rebecca Collier; Northern Clinical Genetics Service, Newcastle, UK: Fiona Douglas, Oonagh Claber and Irene Jobson; Oxford Regional Genetics Service, Oxford, UK: Lisa Walker, Diane McLeod, Dorothy Halliday, Sarah Durell and Barbara Stayner; The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London: Ros Eeles, Susan Shanley, Nazneen Rahman, Richard Houlston, Elizabeth Bancroft, Elizabeth Page, Audrey Ardern-Jones, Kelly Kohut, Jennifer Wiggins, Elena Castro, Emma Killick, Sue Martin, Gillian Rea and Anjana Kulkarni; North Trent Clinical Genetics Service, Sheffield, UK: Jackie Cook, Oliver Quarrell and Cathryn Bardsley; South West Thames Regional Genetics Service, London: Shirley Hodgson, Sheila Goff, Glen Brice, Lizzie Winchester, Charlotte Eddy, Vishakha Tripathi, Virginia Attard and Anna Lehmann; Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK: Diana Eccles, Anneke Lucassen, Gillian Crawford, Donna McBride and Sarah Smalley; and JoEllen Weaver and Dr Betsy Bove for their technical support.
Genetic Modifiers of Cancer Risk in BRCA1/2 Mutation Carriers (GEMO) study
: National Cancer Genetics Network UNICANCER Genetic Group, France; GEMO Collaborating Centers: coordinating centers, Unité Mixte de Génétique Constitutionnelle des Cancers Fréquents, Hospices Civils de Lyon – Centre Léon Bérard, and equipe Génétique du cancer du sein, Centre de Recherche en Cancérologie de Lyon: Olga Sinilnikova, Sylvie Mazoyer, Francesca Damiola, Laure Barjhoux, Carole Verny-Pierre, Alain Calender, Sophie Giraud and Mélanie Léone; and Service de Génétique Oncologique, Institut Curie, Paris: Dominique Stoppa-Lyonnet, Marion Gauthier-Villars, Bruno Buecher, Claude Houdayer, Virginie Moncoutier, Muriel Belotti, Carole Tirapo, Antoine de Pauw. Institut Gustave Roussy, Villejuif, France: Brigitte Bressac-de-Paillerets and Olivier Caron; Centre Jean Perrin, Clermont-Ferrand, France: Yves-Jean Bignon and Nancy Uhrhammer; Centre Léon Bérard, Lyon, France: Christine Lasset, Valérie Bonadona and Sandrine Handallou; Centre François Baclesse, Caen, France: Agnès Hardouin and Pascaline Berthet; Institut Paoli Calmettes, Marseille, France: Hagay Sobol, Violaine Bourdon, Tetsuro Noguchi, Audrey Remenieras and François Eisinger; Centre Hospitalier Régional Universitaire Arnaud-de-Villeneuve, Montpellier, France: Isabelle Coupier and Pascal Pujol; Centre Oscar Lambret, Lille, France: Jean-Philippe Peyrat, Joëlle Fournier, Françoise Révillion, Philippe Vennin and Claude Adenis; Hôpital René Huguenin, Institut Curie, Saint-Cloud, France: Etienne Rouleau, Rosette Lidereau, Liliane Demange and Catherine Nogues; Centre Paul Strauss, Strasbourg, France: Danièle Muller and Jean-Pierre Fricker; Institut Bergonié, Bordeaux, France: Emmanuelle Barouk-Simonet, Françoise Bonnet, Virginie Bubien, Nicolas Sevenet and Michel Longy; Institut Claudius Regaud, Toulouse, France: Christine Toulas, Rosine Guimbaud, Laurence Gladieff and Viviane Feillel; Centre Hospitalier Universitaire de Grenoble, Grenoble, France: Dominique Leroux, Hélène Dreyfus, Christine Rebischung and Magalie Peysselon; Centre Hospitalier Universitaire de Dijon, Dijon, France: Fanny Coron and Laurence Faivre; Centre Hospitalier Universitaire de Saint-Etienne, Saint-Etienne, France: Fabienne Prieur, Marine Lebrun and Caroline Kientz. Hôtel Dieu Centre Hospitalier, Chambéry, France: Sandra Fert Ferrer; Centre Antoine Lacassagne, Nice, France: Marc Frénay; Centre Hospitalier Universitaire de Limoges, Limoges, France: Laurence Vénat-Bouvet; Centre Hospitalier Universitaire de Nantes, Nantes, France: Capucine Delnatte; Centre Hospitalier Universitaire de Bretonneau, Tours, France: Isabelle Mortemousque; Groupe Hospitalier Pitié-Salpétrière, Paris: Florence Coulet, Chrystelle Colas and Florent Soubrier; Centre Hospitalier Régional Universitaire de Nancy, Vandœuvre-lès-Nancy, France: Johanna Sokolowska and Myriam Bronner; Hôpital Jean Minjoz, Centre Hospitalier Universitaire de Besançon, France: Marie-Agnès Collonge-Rame and Alexandre Damette; Creighton University, Omaha, NE, USA: Henry T Lynch and Carrie L Snyder; the technical support of Ilse Coene en Brecht Crombez; and the investigators of the Australia New Zealand Gynaecological Oncology Group (ANZGOG). We acknowledge Alicia Tosar for her technical assistance; Taru A Muranen, Drs Carl Blomqvist and Kirsimari Aaltonen, and registered nurses Irja Erkkilä and Virpi Palola for their help with the Helsinki Breast Cancer Study (HEBCS) data and samples.
The Hereditary Breast and Ovarian Cancer Research Group Netherlands (HEBON)
: collaborating centers: Netherlands Cancer Institute, Amsterdam: MA Rookus, FBL Hogervorst, FE van Leeuwen, S Verhoef, MK Schmidt, JL de Lange and R Wijnands; Erasmus Medical Center, Rotterdam, the Netherlands: JM Collée, AMW van den Ouweland, MJ Hooning, C Seynaeve, CHM van Deurzen and IM Obdeijn; Leiden University Medical Center, Leiden, the Netherlands: CJ van Asperen, JT Wijnen, RAEM Tollenaar, P Devilee and TCTEF van Cronenburg; Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands: CM Kets and AR Mensenkamp; University Medical Center Utrecht, Utrecht, the Netherlands: MGEM Ausems and RB van der Luijt; Amsterdam Medical Center, Amsterdam: CM Aalfs and TAM van Os; VU University Medical Center, Amsterdam: JJP Gille, Q Waisfisz and HEJ Meijers-Heijboer; University Hospital Maastricht, Maastricht, the Netherlands: EB Gómez-Garcia and MJ Blok; University Medical Center Groningen, Groningen, the Netherlands: JC Oosterwijk, AH van der Hout, MJ Mourits and GH de Bock; The Netherlands Foundation for the Detection of Hereditary Tumors, Leiden, the Netherlands: HF Vasen; The Netherlands Cancer Registry: S Siesling; The Dutch Pathology Registry (PALGA): LIH Overbeek; Hong Kong Sanatorium & Hospital for their continual support; Janos Papp, Tibor Vaszko, Aniko Bozsik, Timea Pocza, Judit Franko, Maria Balogh, Gabriella Domokos, Judit Ferenczi (Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary) and the clinicians and patients for their contributions to this study; the Oncogenetics Group and the High Risk and Cancer Prevention Unit of the University Hospital Vall d’Hebron, Barcelona, Spain, led by Dr J Balmaña; the ICO Hereditary Cancer Program team led by Dr Gabriel Capella; Dr Martine Dumont and Martine Tranchant for sample management and skillful technical assistance; JS and PS were part of the quality control and genotyping coordinating group of iCOGS (BCAC and CIMBA); Drs Ana Peixoto, Catarina Santos, Patrícia Rocha and Pedro Pinto for their skillful contributions to the study; Heather Thorne, Eveline Niedermayr, all the kConFab research nurses and staff, the heads and staff of the Family Cancer Clinics, and the clinical follow-up study (which has received funding from the National Health and Medical Research Council (NHMRC), the National Breast Cancer Foundation, Cancer Australia and the National Institutes of Health (Bethesda, MD, USA)) for their contributions to this resource; and the many families who contribute to Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer (kConFab); Lenka Foretova and Eva Machackova (Department of Cancer Epidemiology and Genetics, Masaryk Memorial Cancer Institute, and the Medical Faculty, Masaryk University, Brno, Czech Republic); Michal Zikan, Petr Pohlreich and Zdenek Kleibl (Oncogynecologic Center and Department of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic); Anne Lincoln and Lauren Jacobs; the National Israeli Cancer Control Center (NICCC) National Familial Cancer Consultation Service team led by Sara Dishon; the laboratory team led by Dr Flavio Lejbkowicz; and the research field operations team led by Dr Mila Pinchev; members and participants in the Ontario Cancer Genetics Network for their contributions to the study. Leigha Senter, Kevin Sweet, Caroline Craven and Michelle O’Conor were instrumental in accrual of study participants, ascertainment of medical records and database management; The Ohio State University Human Genetics Sample Bank; the Meirav Breast Center team at the Sheba Medical Center; Åke Borg, Håkan Olsson, Helena Jernström, Karin Henriksson, Katja Harbst, Maria Soller and Ulf Kristoffersson; Sahlgrenska University Hospital, Gothenburg, Sweden: Anna Öfverholm, Margareta Nordling, Per Karlsson and Zakaria Einbeigi; Stockholm and Karolinska University Hospital, Stockholm: Anna von Wachenfeldt, Annelie Liljegren, Annika Lindblom, Brita Arver, Gisela Barbany Bustinza and Johanna Rantala; Umeå University Hospital, Umeå, Sweden: Beatrice Melin, Christina Edwinsdotter Ardnor and Monica Emanuelsson; Uppsala University, Uppsala, Sweden: Hans Ehrencrona, Maritta Hellström Pigg and Richard Rosenquist; Linköping University Hospital, Linköping, Sweden: Marie Stenmark-Askmalm and Sigrun Liedgren; Cecilia Zvocec, Qun Niu, and physicians, genetic counselors, research nurses and staff of the Comprehensive Cancer Risk and Prevention Clinic of University of Chicago Medicine, Chicago, IL, USA, for their contributions to this resource; Joyce Seldon, MSGC, and Lorna Kwan, MPH; Dr Robert Nussbaum and the following genetic counselors: Beth Crawford, Kate Loranger, Julie Mak, Nicola Stewart, Robin Lee, Amie Blanco and Peggy Conrad; Salina Chan; Paul DP Pharoah, Simon Gayther, Susan Ramus, Carole Pye, Patricia Harrington and Eva Wozniak for their contributions to the UK Familial Ovarian Cancer Registry (UKFOCR); Geoffrey Lindeman, Marion Harris, Martin Delatycki of the Victorian Familial Cancer Trials Group; and Sarah Sawyer, Rebecca Driessen and Ella Thompson.
Funding Higher-level funding: The COGS project is funded through a European Commission Seventh Framework Program grant (agreement number 223175: HEALTH-F2-2009-223175). The CIMBA data management and data analysis were supported by Cancer Research UK grants C12292/A11174 and C1287/A10118. SH is supported by a National Health and Medical Research Council (NHMRC) program grant (to GCT).
Individual researcher support
: ACA is a Cancer Research UK Senior Cancer Research Fellow (C12292/A11174). DFE is a Principal Research Fellow of Cancer Research UK. GC, MCS and IC are supported by the National Health and Medical Research Council (NHMRC). BK holds an American Cancer Society Early Detection Professorship (SIOP-06-258-01-COUN). MHG and PLM were supported by funding from the Intramural Research Program of the National Cancer Institute, National Institutes of Health. OIO is an American Cancer Society Clinical Research Professor. JS is Chairholder of the Canada Research Chair in Oncogenetics.
Funding of constituent studies
: The Breast Cancer Family Registry (BCFR) was supported by grant UM1 CA164920 from the National Cancer Institute, National Institutes of Health. The content of this article does not necessarily reflect the views or policies of the National Cancer Institute or any of the collaborating centers in the BCFR, nor does mention of trade names, commercial products or organizations imply endorsement by the US Government or the BCFR. The Baltic Familial Breast Ovarian Cancer Consortium (BFBOCC) is partly supported by Lithuania (BFBOCC-LT): Research Council of Lithuania grant LIG-07/2012; BFBOCC-LV (Latvia) is partly supported by LSC grant 10.0010.08 and in part by a grant from the European Social Fund number 2009/0220/1DP/1.1.1.2.0/09/APIA/VIAA/016 and the Liepāja City Council, Liepāja, Latvia; Beth Israel Deaconess Medical Center Cancer Center is supported by the Breast Cancer Research Foundation; BRCA-gene mutations and breast cancer in South African women (BMBSA) was supported by grants from the Cancer Association of South Africa (CANSA) to Elizabeth J van Rensburg; SLN (Beckman Research Institute, City of Hope, Duarte, CA, USA) was partially supported by the Morris and Horowitz Families Professorship in Cancer Etiology and Outcomes Research; the Copenhagen Breast Cancer Study (CBCS) was supported by the NEYE Foundation; the Spanish National Cancer Research Center (Centro Nacional de Investigaciones Oncológicas (CNIO)) was partially supported by the Spanish Association against Cancer (Asociación Española Contra el Cáncer AECC08), Thematic Network Cooperative Research in Cancer (Red Temática Investigación Cooperativa en Cáncer (RTICC), Centro de Investigación Cáncer, Salamanca, Spain) RTICC 06/0020/1060, Spanish Ministry of Science and Innovation grants FIS PI08 1120 (Fondo de Investigación Sanitaria (FIS)) and SAF2010-20493, and the Fundación Mutua Madrileña (FMMA); the City of Hope Clinical Cancer Genetics Community Network and the Hereditary Cancer Research Registry (COH-CCGCRN), supported in part by award number RC4CA153828 (Principal Investigator: JNW) from the National Cancer Institute and the Office of the Director, National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
CONsorzio Studi ITaliani sui Tumori Ereditari Alla Mammella, Italy
(
CONSIT Team
): Funds from Italian citizens who allocated the “5 × 1,000” share of their tax payment in support of the Fondazione IRCCS Istituto Nazionale Tumori, according to Italian laws (Istituto Nazionale dei Tumori (INT) institutional strategic project “5 × 1,000”) (to SM); the Italian Association for Cancer Research (AIRC) (to LO); National Centre for Scientific Research “Demokritos” has been cofinanced by the European Union (European Social Fund (ESF)) and Greek national funds through the “Education and Lifelong Learning” operational program of the National Strategic Reference Framework (NSRF) – Research Funding Program of the General Secretariat for Research and Technology: ARISTEIA; “Heracleitus II: Investing in knowledge society through the European Social Fund”; the DKFZ study was supported by the Deutsches Krebsforschungszentrum (DKFZ); Epidemiological Study of BRCA1 and BRCA2 Mutation Carriers (EMBRACE) is supported by Cancer Research UK grants C1287/A10118 and C1287/A11990; DGE and FL are supported by a National Institute for Health Research (NIHR) grant to the Biomedical Research Centre, Manchester, UK; the investigators at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust are supported by an NIHR grant to the Biomedical Research Centre at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London; RE and EB are supported by Cancer Research UK grant C5047/A8385; Kansas University Medical Center: The authors acknowledge support from The University of Kansas Cancer Center (P30 CA168524) and the Kansas Bioscience Authority Eminent Scholar Program; AKG was funded by grants 5U01 CA113916 and R01 CA140323 and by the Chancellors Distinguished Chair in Biomedical Sciences Professorship; The German Consortium of Hereditary Breast and Ovarian Cancer (GC-HBOC) is supported by German Cancer Aid (grant 109076 (to RKS) and by the Center for Molecular Medicine Cologne (CMMC); GC-HBOC is deeply grateful to Dr Sabine Preisler-Adam for providing information and samples; the GEMO Study was supported by the Ligue National Contre le Cancer; the Association “Le cancer du sein, parlons-en!” Award; and the Canadian Institutes of Health Research for the CIHR Team in Familial Risks of Breast Cancer program; G-FAST: KDL is supported by GOA grant BOF10/GOA/019 (Ghent University) and spearhead financing of Ghent University Hospital; the Gynecologic Oncology Group (GOG) was supported by National Cancer Institute grants to the GOG Administrative Office and Tissue Bank (grant CA 27469), the GOG Statistical and Data Center (grant CA 37517) and GOG’s Cancer Prevention and Control Committee (grant CA 101165); HCSC was supported by grants RD12/00369/0006 and 12/00539 from Instituto de Salud Carlos III (ISCIII), Madrid, Spain, partially supported by European Regional Development Fund (Fonds européen de développement régional (FEDER)) funds; the Helsinki Breast Cancer Study (HEBCS) was financially supported by the Helsinki University Central Hospital Research Fund, Academy of Finland (266528), the Finnish Cancer Society and the Sigrid Juselius Foundation; HEBON is supported by the Dutch Cancer Society grants NKI1998-1854, NKI2004-3088 and NKI2007-3756, the Netherlands Organization of Scientific Research grant NWO 91109024, the Pink Ribbon grant 110005 and Biobanking and Molecular Resource Infrastructure (BBMRI) grant NWO 184.021.007/CP46; HEBON thanks the registration teams of the Comprehensive Cancer Centre Netherlands and Comprehensive Centre South (together the Netherlands Cancer Registry) and PALGA (Dutch Pathology Registry) for part of the data collection; the High Risk Breast Cancer Program (HRBCP) is supported by the Hong Kong Hereditary Breast Cancer Family Registry and the Dr Ellen Li Charitable Foundation, Hong Kong; the Hungarian Breast and Ovarian Cancer Study (HUNBOCS) was supported by Hungarian Research and Technological Innovation Fund (KTIA)/Hungarian Scientific Research Fund (Országos Tudományos Kutatási Alapprogramok (OTKA)) research grants KTIA-OTKA CK-80745 and KTIA-OTKA K-112228; Institut Català d’Oncologia (ICO): contract grant sponsor: Asociación Española Contra el Cáncer; Spanish Health Research Foundation; Ramón Areces Foundation; Instituto de Salud Carlos III (ISCIII); Catalan Health Institute; and Autonomous Government of Catalonia; contract grant numbers ISCIIIRETIC RD06/0020/1051, PI09/02483, PI10/01422, PI10/00748, PI13/00285, PI13/00189 2009SGR290 and PI13/00189 2009SGR283; the International Hereditary Cancer Center (Department of Genetics and Pathology, Pomeranian Medical University, Szczecin, Poland) was supported by grant PBZ_KBN_122/P05/2004; Landspitali – The National University Hospital of Iceland was supported by the Icelandic Association “Walking for Breast Cancer Research” and by the Landspitali University Hospital Research Fund; the Interdisciplinary Health Research Internal Team Breast Cancer Susceptibility Study (INHERIT) was supported by the Canadian Institutes of Health Research (CIHR) for the “CIHR Team in Familial Risks of Breast Cancer” program, Canadian Breast Cancer Research Alliance grant 019511 and Ministry of Economic Development, Innovation and Export Trade grant PSR-SIIRI-701; the Istituto Oncologico Veneto Hereditary Breast and Ovarian Cancer Study (IOVHBOCS) is supported by the Ministero della Salute and a “5 × 1,000” Istituto Oncologico Veneto grant; the Portuguese Oncology Institute–Porto Breast Cancer Study (IPOBCS) was supported in part by Liga Portuguesa Contra o Cancro; kConFab is supported by a grant from the National Breast Cancer Foundation and previously by the National Health and Medical Research Council (NHMRC), the Queensland Cancer Fund, the Cancer Councils of New South Wales, Victoria, Tasmania and South Australia, and the Cancer Foundation of Western Australia; the Mayo Clinic is supported by National Institutes of Health (NIH) grants CA 116167, CA 128978 and CA 176785 through the National Cancer Institute (NCI), an NCI Specialized Program of Research Excellence (SPORE) in Breast Cancer (CA116201), a US Department of Defense Ovarian Cancer Idea award (W81XWH-10-1-0341), a grant from the Breast Cancer Research Foundation, a generous gift from the David F and Margaret T Grohne Family Foundation and the Ting Tsung and Wei Fong Chao Foundation; McGill University Jewish General Hospital Weekend to End Breast Cancer, Quebec Ministry of Economic Development, Innovation and Export Trade; Modifier Study of Quantitative Effects on Disease (ModSQuaD) was supported by the Ministry of Health of the Czech Republic to Masaryk Memorial Cancer Institute (MH CZ – DRO) (MMCI 00209805) and by the European Regional Development Fund and the State Budget of the Czech Republic (RECAMO, CZ.1.05/2.1.00/03.0101) (to LF), and by Charles University in Prague project UNCE204024 (MZ); Memorial Sloan Kettering Cancer Center (MSKCC) is supported by grants from the Breast Cancer Research Foundation and Robert and Kate Niehaus Clinical Cancer Genetics Initiative; National Cancer Institute, National Institutes of Health: The research of MHG and PLM was supported by the Intramural Research Program of the National Cancer Institute and by support services contracts N02-CP-11019-50 and N02-CP-65504 with Westat, Inc, Rockville, MD, USA; the National Israeli Cancer Control Center (NICCC) is supported by Clalit Health Services in Israel; some of its activities are supported by the Israel Cancer Association and the Breast Cancer Research Foundation (BCRF), New York, NY, USA; NN Petrov Institute of Oncology has been supported by the Russian Federation for Basic Research (grants 11-04-00227, 12-04-00928 and 12-04-01490) and the Federal Agency for Science and Innovations, Russia (contract 02.740.11.0780); The Ohio State University Clinical Cancer Genetics (OSUCCG) is supported by The Ohio State University Comprehensive Cancer Center; the Pisa Breast Cancer Study (PBCS) was supported by Istituto Toscano Tumori (ITT) grants 2011–2013; Sheba Medical Center was partially funded through a grant from the Israel Cancer Association and funding for the Israeli Inherited Breast Cancer Consortium; the Swedish Breast Cancer Study collaborators are supported by the Swedish Cancer Society; The University of Chicago is supported by NCI Specialized Program of Research Excellence (SPORE) in Breast Cancer (CA125183), R01 CA142996 and 1U01CA161032 and by the Ralph and Marion Falk Medical Research Trust, the Entertainment Industry Fund National Women’s Cancer Research Alliance and the Breast Cancer Research Foundation; University of California, Los Angeles Jonsson Comprehensive Cancer Center Foundation: Breast Cancer Research Foundation; University of California, San Francisco Cancer Risk Program and Helen Diller Family Comprehensive Cancer Center; UK Familial Ovarian Cancer Registry (UKFOCR) was supported by a project grant from Cancer Research UK (to Paul DP Pharoah); the University of Pennsylvania: National Institutes of Health (NIH) grants R01 CA102776 and R01 CA083855; the Breast Cancer Research Foundation; the Susan G Komen for the Cure, Basser Center for BRCA; Victorian Familial Cancer Trials Group (VFCTG): Victorian Cancer Agency, Cancer Australia, National Breast Cancer Foundation; The Women’s Cancer Program (WCP) at the Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, is funded by the American Cancer Society Early Detection Professorship (SIOP-06-258-01-COUN).
GEMO Study
: National Cancer Genetics Network UNICANCER Genetic Group, France.
The Hereditary Breast and Ovarian Cancer Research Group Netherlands (HEBON) coordinating center
: Netherlands Cancer Institute, Amsterdam.
Authors’ contributions
Conception and design: DGC and GT. Development of methodology: SB, CBa and VD. Acquisition of data: LM, SHe, DB, ALe, JD, KBK, PS, MBT, WKC, DEG, SSB, RJ, LT, NT, CMD, EJvR, SLN, YCD, AMG, BE, FCN, TvOH, AO, JBe, RA, ES, JNW, MThe, PP, PR, VP, RDo, BB, BP, DZ, GSc, SMan, LV, GLC, LP, LO, DY, IK, JGa, UH, AD, ABr, CBr, CF, DGE, DF, DE, FDo, JCo, JA, JBa, LW, LI, LES, MJK, MTi, MTR, MEP, PJM, RP, RE, RDa, SHo, TCo, AKG, CI, KC, KDL, AM, AG, BW, CS, CE, DN, DS, HP, KK, KR, ND, NA, RV, RKS, SP, NB, SW, AdP, CLe, CLas, DL, ER, FDa, GSC, HD, LB, LG, NU, VB, VS, YB, JCa, LVL, MP, PAD, MdlH, TCa, HN, KA, AJag, AMvdO, CMK, CMA, FEvL, FBH, HEM, JCO, KvR, MAR, PD, RBvdL, EO, OD, AT, CLaz, IB, JDV, AJak, GSu, JGr, JLu, KD, KJ, BAA, CM, AA, MM, MRT, ABS, WF, CO, NLi, VSP, CIS, ALinc, LJ, MC, MR, JV, ABe, AF, CFS, CR, DGK, GP, MTe, MHG, PLM, GR, EI, AMM, GG, ILA, ST, AET, ISP, MTho, TAK, UBJ, MAC, EF, JZ, YL, ALind, BM, BA, NLo, RR, OIO, RLN, SR, KLN, SMD, TRR, BKA, GM, BYK, JLe, SO, DSL, GT, JS, FJC, KO, DFE, GC, ACA, SMaz, CMP and OMS. Analysis and interpretation of data: SB, DGC and ACA. Writing of the manuscript: SB, DGC, ACA, SH, ABS, GC, SLN, AET, ILA, JCO, KO, MTho and GM. All authors read and approved the final manuscript.