title: Adjuvant trastuzumab with chemotherapy is effective in women with small, node-negative, HER2-positive breast cancer.
abstract: BACKGROUND
  Several large, randomized trials established the benefits of adjuvant trastuzumab with chemotherapy. However, the benefit for women with small, node-negative HER2-positive (HER2+) disease is unknown, as these patients were largely excluded from these trials. Therefore, a retrospective, single-institution, sequential cohort study of women with small, node-negative, HER2+ breast cancer who did or did not receive adjuvant trastuzumab was conducted.
  
  
  METHODS
  Women with ≤ 2 cm, node-negative, HER2+ (immunohistochemistry 3+ or fluorescence in situ hybridization ≥ 2) breast cancer were identified through an institutional database. A "no-trastuzumab" cohort of 106 trastuzumab-untreated women diagnosed between January 1, 2002 and May 14, 2004 and a "trastuzumab" cohort of 155 trastuzumab-treated women diagnosed between May 16, 2005 and December 31, 2008 were described. Survival and recurrence outcomes were estimated by Kaplan-Meier methods.
  
  
  RESULTS
  The cohorts were similar in age, median tumor size, histology, hormone receptor status, hormone therapy, and locoregional therapy. Chemotherapy was administered in 66% and 100% of the "no trastuzumab" and "trastuzumab" cohorts, respectively. The median recurrence-free and survival follow-up was: 6.5 years (0.7-8.5) and 6.8 years (0.7-8.5), respectively, for the "no trastuzumab" cohort and 3.0 years (0.5-5.2) and 3.0 years (0.6-5.2), respectively, for the "trastuzumab" cohort. The 3-year locoregional invasive recurrence-free, distant recurrence-free, invasive disease-free, and overall survival were 92% versus 98% (P = .0137), 95% versus 100% (P = .0072), 82% versus 97% (P < .0001), and 97% versus 99% (P = .18) for the "no trastuzumab" and "trastuzumab" cohorts, respectively.
  
  
  CONCLUSIONS
  Women with small, node-negative, HER2+ primary breast cancers likely derive significant benefit from adjuvant trastuzumab with chemotherapy.
authors.affiliation: Breast Cancer Medicine Service, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA. mcarthuh@mskcc.org
authors.forename: Heather L
authors.initials: HL
authors.lastname: McArthur
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Mahoney
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Morris
authors.forename: Sujata
authors.initials: S
authors.lastname: Patil
authors.forename: Lindsay M
authors.initials: LM
authors.lastname: Jacks
authors.forename: Jane
authors.initials: J
authors.lastname: Howard
authors.forename: Larry
authors.initials: L
authors.lastname: Norton
authors.forename: Clifford A
authors.initials: CA
authors.lastname: Hudis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D016032:Randomized Controlled Trials as Topic; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D012189:Retrospective Studies; D000068878:Trastuzumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab