title: Axillary Lymph Node Status in Early-Stage Breast Cancer Patients with Sentinel Node Micrometastases (0.2-2 mm).
abstract: BACKGROUND
  Omission of axillary lymph node dissection (ALND) is increasingly becoming the new standard of care for patients with sentinel lymph node micrometastases (SNMMs). However, a formidable proportion of patients is afflicted with non-sentinel node (NSN) macrometastatic tumor burden.
  
  
  METHODS
  Over 1 decade 5,000 patients underwent sentinel node biopsies (SNB) at 2 certified breast cancer centers in Austria. All available cases of SNMM during this time period were reviewed. Clinical, tumor and lymph node parameters were analyzed using univariate and multivariate analysis to retrieve predictors for further NSN involvement.
  
  
  RESULTS
  We identified 216 patients with SNMMs, of whom 181 subsequently underwent ALND. Of the latter patients, 16% (n = 29/181) presented with NSN axillary metastases. ALND revealed NSN macrometastases in 10.5% (n = 19/181) of all the investigated patients, and 66% of the NSN-positive patients (n = 19/29). In 28% (n = 8/29) of the NSN-positive patients, more than 1 macrometastasis was detected. The number of removed sentinel nodes was found to be a significant predictor (p = 0.007) for NSN involvement.
  
  
  CONCLUSIONS
  In this retrospective investigation of breast cancer patients with SNMMs, a substantial proportion exhibited involvement of NSNs. Macrometastases accounted for the largest fraction of NSN tumor burden. Refraining from ALND in the face of SNMMs may entail substantial micro- and macrometastatic tumor burden in the remaining axillary lymph node basin.
authors.affiliation: Breast Center, Paracelsus Medical University Salzburg, Austria ; Department of Obstetrics and Gynecology, Innsbruck Medical University, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Bargehr
authors.affiliation: Department of Medical Statistics, Informatics and Health Economics, Innsbruck Medical University, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Edlinger
authors.affiliation: Department of Obstetrics and Gynecology, Innsbruck Medical University, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Hubalek
authors.affiliation: Department of Obstetrics and Gynecology, Innsbruck Medical University, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Marth
authors.affiliation: Breast Center, Paracelsus Medical University Salzburg, Austria.
authors.forename: Roland
authors.initials: R
authors.lastname: Reitsamer
keywords: Biopsy; Breast cancer; Lymph node: dissection, metastases, status; Micrometastases; Risk factors; Sentinel lymph node