title: The evolving understanding of small HER2-positive breast cancers: matching management to outcomes.
abstract: Systemic therapy for small (stage I) HER2-positive breast cancers has long posed a dilemma for clinicians, as the majority of these patients were excluded from the large adjuvant trastuzumab trials. However in the decade since those trials were reported, data have accumulated to suggest that recurrence risk for these small but biologically aggressive tumors is nontrivial. In this review, we summarize data from numerous cohort studies describing the outcomes of small HER2-positive tumors, mostly in the absence of HER2-directed therapy. We then examine the potential impact of HER2-directed treatment in this population, culminating in the recently published prospective study of paclitaxel/trastuzumab therapy. The landscape of next generation anti-HER2 therapies is quickly evolving; a role for some of these agents in the small HER2-positive subpopulation may also be on the horizon.
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: Adrienne G
authors.initials: AG
authors.lastname: Waks
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: Sara M
authors.initials: SM
authors.lastname: Tolaney
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D017024:Chemotherapy, Adjuvant; D019468:Disease Management; D005260:Female; D006801:Humans; D009367:Neoplasm Staging; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000068878:Trastuzumab / Q000008:administration & dosage; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab
keywords: APT trial; ATEMPT trial; HER2; T1abN0; breast cancer; stage I; trastuzumab; trastuzumab–emtansine