title: The adjuvant treatment of HER2-positive breast cancer.
abstract: About 15-20% of patients with early stage breast cancer present with tumors that have overexpression or amplification of the human epidermal growth factor receptor 2 (HER2) gene. Before 2005, these individuals had an increased risk of recurrence and death, but since then their outcomes have substantially improved with the adoption in most countries of adjuvant trastuzumab as a standard component of therapy for HER2-positive early-stage breast cancer. Consequently, access to high-quality and accurate HER2 testing methods is critical to accurately determine HER2 status, guide treatment decisions, and ultimately improve clinical outcomes. In 2012, the humanized monoclonal anti-HER antibody trastuzumab was the only approved HER2-targeted therapy in the adjuvant setting. Data from the first generation of trials combining it with various chemotherapy regimens showed significant improvements in disease-free and overall survival (DFS/OS). Based on results from five randomized clinical trials, a trastuzumab-containing regimen for up to 1 year is now considered standard for all patients with HER2-positive tumors larger than 1 cm in size who would have fulfilled eligibility to those studies, and this recommendation is sometimes extended to patients with stage I tumors greater than 0.5 cm (T1b). Second generation adjuvant studies with other HER2-targeted agents like lapatinib and pertuzumab are ongoing, and newer drugs like T-DM1 and neratinib are being actively tested in the metastatic setting.
authors.affiliation: Breast Cancer Program, The Johns Hopkins Kimmel Comprehensive Cancer Center, Baltimore, MD 21231, USA. djelova1@jhmi.edu
authors.forename: Danijela
authors.initials: D
authors.lastname: Jelovac
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Wolff
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics*; D054715:Cardiotoxins; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D005260:Female; D018734:Genes, erbB-2; D006321:Heart / Q000187:drug effects; D006801:Humans; D000077341:Lapatinib; D011799:Quinazolines / Q000627:therapeutic use; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000276:immunology*; D000068878:Trastuzumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D054715:Cardiotoxins; D000077341:Lapatinib; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human; C485206:pertuzumab