title: Clinical use of biomarkers in breast cancer: Updated guidelines from the European Group on Tumor Markers (EGTM).
abstract: Biomarkers play an essential role in the management of patients with invasive breast cancer. For selecting patients likely to respond to endocrine therapy, both oestrogen receptors (ERs) and progesterone receptors (PRs) should be measured on all newly diagnosed invasive breast cancers. On the other hand, for selecting likely response to all forms of anti-HER2 therapy (trastuzumab, pertuzumab, lapatinib or ado-trastuzumab emtansine), determination of HER2 expression or gene copy number is mandatory. Where feasible, measurement of ER, PR and HER2 should be performed on recurrent lesions and the primary invasive tumour. Although methodological problems exist in the determination of Ki67, because of its clearly established clinical value, wide availability and low costs relative to the available multianalyte signatures, Ki67 may be used for determining prognosis, especially if values are low or high. In oestrogen receptor (ER)-positive, HER2-negative, lymph node-negative patients, multianalyte tests such as urokinase plasminogen activator (uPA)-PAI-1, Oncotype DX, MammaPrint, EndoPredict, Breast Cancer Index (BCI) and Prosigna (PAM50) may be used to predict outcome and aid adjunct therapy decision-making. Oncotype DX, MammaPrint, EndoPredict and Prosigna may be similarly used in patients with 1-3 metastatic lymph nodes. All laboratories measuring biomarkers for patient management should use analytically and clinically validated assays, participate in external quality assurance programs, have established assay acceptance and rejection criteria, perform regular audits and be accredited by an appropriate organisation.
authors.affiliation: Clinical Research Centre, St. Vincent's University Hospital, Dublin and UCD School of Medicine, UCD Conway Institute, University College Dublin, Dublin 4, Ireland. Electronic address: michael.j.duffy@ucd.ie.
authors.forename: M J
authors.initials: MJ
authors.lastname: Duffy
authors.affiliation: Breast Center of the University of Munich, Munich, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Harbeck
authors.affiliation: Department of Pathology, Atrium Heerlen Medical Centre, Heerlen, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Nap
authors.affiliation: Laboratory of Biochemistry, Hospital Clinic, Barcelona, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Molina
authors.affiliation: Department of Oncology, Transplantations and New Technologies in Medicine, University of Pisa, Pisa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Nicolini
authors.affiliation: Department of Oncology and Radiotherapy, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: E
authors.initials: E
authors.lastname: Senkus
authors.affiliation: Breast Unit, Champalimaud Clinical Centre, Lisbon, Portugal.
authors.forename: F
authors.initials: F
authors.lastname: Cardoso
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism / Q000628:therapy*; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D017410:Practice Guidelines as Topic; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D017395:Plasminogen Activator Inhibitor 1; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D014568:Urokinase-Type Plasminogen Activator; C508053:ERBB2 protein, human
keywords: Biomarkers; Breast cancer; EGTM; Gene signatures; Guidelines