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Åke Borg

Åke Borg

Principal investigator

Åke Borg

Comprehensive molecular comparison of BRCA1 hypermethylated and BRCA1 mutated triple negative breast cancers


  • Dominik Glodzik
  • Ana Bosch
  • Johan Hartman
  • Mattias Aine
  • Johan Vallon-Christersson
  • Christel Reuterswärd
  • Anna Karlsson
  • Shamik Mitra
  • Emma Niméus
  • Karolina Holm
  • Jari Häkkinen
  • Cecilia Hegardt
  • Lao H. Saal
  • Christer Larsson
  • Martin Malmberg
  • Lisa Rydén
  • Anna Ehinger
  • Niklas Loman
  • Anders Kvist
  • Hans Ehrencrona
  • Serena Nik-zainal
  • Åke Borg
  • Johan Staaf

Summary, in English

Homologous recombination deficiency (HRD) is a defining characteristic in BRCA-deficient breast tumors caused by genetic or epigenetic alterations in key pathway genes. We investigated the frequency of BRCA1 promoter hypermethylation in 237 triple-negative breast cancers (TNBCs) from a population-based study using reported whole genome and RNA sequencing data, complemented with analyses of genetic, epigenetic, transcriptomic and immune infiltration phenotypes. We demonstrate that BRCA1 promoter hypermethylation is twice as frequent as BRCA1 pathogenic variants in early-stage TNBC and that hypermethylated and mutated cases have similarly improved prognosis after adjuvant chemotherapy. BRCA1 hypermethylation confers an HRD, immune cell type, genome-wide DNA methylation, and transcriptional phenotype similar to TNBC tumors with BRCA1-inactivating variants, and it can be observed in matched peripheral blood of patients with tumor hypermethylation. Hypermethylation may be an early event in tumor development that progress along a common pathway with BRCA1-mutated disease, representing a promising DNA-based biomarker for early-stage TNBC.


  • Breastcancer-genetics
  • LUCC: Lund University Cancer Centre
  • Molecular therapeutics in breast cancer
  • Division of Molecular Hematology (DMH)
  • Breast/lungcancer
  • StemTherapy: National Initiative on Stem Cells for Regenerative Therapy
  • Research Group Lung Cancer
  • Melanoma
  • Melanoma Genomics
  • Breast Cancer Surgery
  • Breast cancer Proteogenomics
  • Biomarkers and epidemiology
  • Translational Oncogenomics
  • Transl oncogenomics
  • Tumor Cell Biology
  • Division of Translational Cancer Research
  • Breast cancer treatment
  • The Liquid Biopsy and Tumor Progression in Breast Cancer
  • Surgery (Lund)
  • Pathology, Lund
  • Breast/ovarian cancer
  • Familial Breast Cancer
  • Division of Clinical Genetics

Publishing year





Nature Communications





Document type

Journal article


Nature Publishing Group


  • Cancer and Oncology
  • Medical Genetics




  • Sweden Cancerome Analysis Network - Breast (SCAN-B): a large-scale multicenter infrastructure towards implementation of breast cancer genomic analyses in the clinical routine

Research group

  • Molecular therapeutics in breast cancer
  • Research Group Lung Cancer
  • Melanoma Genomics
  • Breast Cancer Surgery
  • Breast cancer Proteogenomics
  • Translational Oncogenomics
  • Tumor Cell Biology
  • The Liquid Biopsy and Tumor Progression in Breast Cancer
  • Familial Breast Cancer


  • ISSN: 2041-1723