title: Characteristics and treatment of human epidermal growth factor receptor 2 positive breast cancer: 43,485 cases from the National Cancer Database treated in 2010 and 2011.
abstract: BACKGROUND
  Although identification of human epidermal growth factor receptor 2 (Her2) positive breast cancer represents one of the greatest advances over the past 3 decades, it has not been studied extensively on a national level.
  
  
  METHODS
  The National Cancer Database is a joint project of the American Cancer Society and the American College of Surgeons and contains data on about 70% of the cancer cases in the United States. Data on Her2 have been collected since 2010 and was used for this study.
  
  
  RESULTS
  Of 298,937 cases of invasive breast cancer with known Her2 status diagnosed in 2010 and 2011, 43,485 (14.5%) were Her2 positive. Her2 positivity was greatest in Asian/Pacific Islanders and least in non-Hispanic Whites and was markedly more common in younger women. The incidence of Her2 positive tumors ranged from a low of 13.9% in the Mountain West region to a high of 16.0% in the West South Central region (P < .001). Compared with Her2 negative tumors, Her2 positive tumors were larger (2.6 vs 2.2 cm, P < .001), more likely to have positive nodes (39% vs 31% P < .001), have lymphovascular invasion (30% vs 20%, P < .001), and be high grade (56% vs 29%, P < .001). There were also differences by histology: invasive ductal 16.4%, invasive lobular 5.5%, tubular 2.3%, inflammatory 36%, and Paget's with invasion 59%. When adjusted for age, race, tumor size, and nodal status Her2 positive tumors were much more likely to receive chemotherapy (odds ratio = 5.5, confidence interval = 5.2 to 6.0) and somewhat less likely to undergo breast preservation (odds ratio = .78, confidence interval = .76 to .80).
  
  
  CONCLUSIONS
  Her2 positive tumors have distinct epidemiologic, clinical, and treatment characteristics.
authors: Department of Surgery, Yale University School of Medicine, The Breast Center, Smilow Cancer Hospital at Yale-New Haven, 20 York Street North Pavilion, First Floor, New Haven, CT 06510, USA. Electronic address: brigid.killelea@yale.edu.
authors: Brigid K
authors: BK
authors: Killelea
authors: Department of Surgery, Yale University School of Medicine, The Breast Center, Smilow Cancer Hospital at Yale-New Haven, 20 York Street North Pavilion, First Floor, New Haven, CT 06510, USA.
authors: Anees B
authors: AB
authors: Chagpar
authors: Department of Surgery, Yale University School of Medicine, The Breast Center, Smilow Cancer Hospital at Yale-New Haven, 20 York Street North Pavilion, First Floor, New Haven, CT 06510, USA.
authors: Nina R
authors: NR
authors: Horowitz
authors: Department of Surgery, Yale University School of Medicine, The Breast Center, Smilow Cancer Hospital at Yale-New Haven, 20 York Street North Pavilion, First Floor, New Haven, CT 06510, USA.
authors: Donald R
authors: DR
authors: Lannin
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology / Q000378:metabolism* / Q000473:pathology / Q000628:therapy*; D018270:Carcinoma, Ductal, Breast / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D018275:Carcinoma, Lobular / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D017024:Chemotherapy, Adjuvant / Q000706:statistics & numerical data; D016208:Databases, Factual; D005260:Female; D006801:Humans; D015994:Incidence; D058922:Inflammatory Breast Neoplasms / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D008207:Lymphatic Metastasis; D008297:Male; D008408:Mastectomy / Q000706:statistics & numerical data; D015412:Mastectomy, Segmental / Q000706:statistics & numerical data; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010144:Paget's Disease, Mammary / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D044469:Racial Groups / Q000706:statistics & numerical data; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D014481:United States / Q000453:epidemiology
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases
keywords: Breast cancer; Breast cancer epidemiology; Breast cancer treatment; Her2 positive breast cancer