title: The clinical impact and outcomes of immunohistochemistry-only metastasis in breast cancer.
abstract: BACKGROUND
  Modern surgical and pathological techniques can detect small-volume axillary metastases in breast cancer with unknown clinical significance.
  
  
  METHODS
  A retrospective database review from 1996 through 2004 identified all patients with immunohistochemical (IHC)-only sentinel node (IHC-SN) metastases and compared them with negative controls (Neg-SN).
  
  
  RESULTS
  When comparing the 232 IHC-SN patients with the 252 Neg-SN controls, the IHC-SN patients had larger tumors, more lobular histology, a higher grade, and more HER2/neu positivity. They also received more systemic therapy. With a median follow-up of 5 years, there were no differences in recurrence-free survival or overall survival. In 123 IHC-SN patients treated with axillary dissection (axillary lymph node dissection), 16% had positive non-SLNs. Patients with positive non-SLNs tended to have worse outcomes.
  
  
  CONCLUSIONS
  IHC-only sentinel lymph node (SLN) metastases were associated with worse prognostic features and higher rates of systemic therapy. However, no outcomes differences were noted.
authors.affiliation: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Pugliese
authors.forename: Michelle
authors.initials: M
authors.lastname: Stempel
authors.forename: Sujata
authors.initials: S
authors.lastname: Patil
authors.forename: Meier
authors.initials: M
authors.lastname: Hsu
authors.forename: Alice
authors.initials: A
authors.lastname: Ho
authors.forename: Tiffany
authors.initials: T
authors.lastname: Traina
authors.forename: Monica
authors.initials: M
authors.lastname: Morrow
authors.forename: Hiram
authors.initials: H
authors.lastname: Cody
authors.forename: Mary L
authors.initials: ML
authors.lastname: Gemignani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla / Q000473:pathology*; D001943:Breast Neoplasms / Q000473:pathology*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000175:diagnosis* / Q000473:pathology; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D021701:Sentinel Lymph Node Biopsy