title: Factors predicting additional disease in the axilla in patients with positive sentinel lymph nodes after neoadjuvant chemotherapy.
abstract: BACKGROUND
  The utility of sentinel lymph node (SNL) biopsy (SLNB) as a predictor of axillary lymph node status is similar in patients who receive neoadjuvant chemotherapy and patients who undergo surgery first. The authors of this study hypothesized that patients with positive SLNs after neoadjuvant therapy would have unique clinicopathologic factors that would be predictive of additional positive non-SLNs distinct from patients who underwent surgery first.
  
  
  METHODS
  One hundred four patients were identified who received neoadjuvant chemotherapy, had a positive SLN, and underwent axillary dissection between 1997 and 2005. At the time of presentation, 66 patients had clinically negative lymph nodes by ultrasonography, and 38 patients had positive lymph nodes confirmed by fine-needle aspiration. Eighteen factors were assessed for their ability to predict positive non-SLNs using chi-square and logistic regression analysis with a bootstrapped, backwards elimination procedure. The resulting nomogram was tested by using a patient cohort from another institution.
  
  
  RESULTS
  Patients with clinically negative lymph nodes at presentation were less likely than patients with positive lymph nodes to have positive non-SLNs (47% vs 71%; P=.017). On multivariate analysis, lymphovascular invasion, the method for detecting SLN metastasis, multicentricity, positive axillary lymph nodes at presentation, and pathologic tumor size retained grouped significance with a bootstrap-adjusted area under the curve (AUC) of 0.762. The resulting nomogram was validated in the external patient cohort (AUC, 0.78).
  
  
  CONCLUSIONS
  A significant proportion of patients with positive SLNs after neoadjuvant chemotherapy had no positive non-SLNs. The use of a nomogram based on 5 predictive variables that were identified in this study may be useful for predicting the risk of positive non-SLNs in patients who have positive SLNs after chemotherapy.
authors.affiliation: Department Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: Jacqueline S
authors.initials: JS
authors.lastname: Jeruss
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Newman
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Ayers
authors.forename: Massimo
authors.initials: M
authors.lastname: Cristofanilli
authors.forename: Kristine R
authors.initials: KR
authors.lastname: Broglio
authors.forename: Funda
authors.initials: F
authors.lastname: Meric-Bernstam
authors.forename: Min
authors.initials: M
authors.lastname: Yi
authors.forename: Jennifer F
authors.initials: JF
authors.lastname: Waljee
authors.forename: Merrick I
authors.initials: MI
authors.lastname: Ross
authors.forename: Kelly K
authors.initials: KK
authors.lastname: Hunt
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla / Q000473:pathology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D019992:Databases as Topic; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D049451:Nomograms; D011237:Predictive Value of Tests; D021701:Sentinel Lymph Node Biopsy