title: Predicting the risk for additional axillary metastases in patients with breast carcinoma and positive sentinel lymph node biopsy.
abstract: OBJECTIVE
  To assess whether the risk for nonsentinel node metastases may be predicted, thus sparing a subgroup of patients with breast carcinoma and a positive sentinel lymph node (SLN) biopsy completion axillary lymph node dissection (ALND).
  
  
  BACKGROUND
  The SLN is the only involved axillary lymph node in the majority of the patients undergoing ALND for a positive SLN biopsy. A model to predict the status of nonsentinel axillary lymph nodes could help tailor surgical therapy to those patients most likely to benefit from completion ALND.
  
  
  METHODS
  All the axillary sentinel and nonsentinel lymph nodes of 1228 patients were reviewed histologically and reclassified according to the current TNM classification of malignant tumors as bearing isolated tumor cells only, micrometastases, or (macro)metastases. The prevalence of metastases in nonsentinel lymph nodes was correlated to the type of SLN involvement and the size of the metastasis, the number of affected SLNs, and the prospectively collected clinicopathologic variables of the primary tumors.
  
  
  RESULTS
  In multivariate analysis, further axillary involvement was significantly associated with the type and size of SLN metastases, the number of affected SLNs, and the occurrence of peritumoral vascular invasion in the primary tumor. A predictive model based on the characteristics most strongly associated with nonsentinel node metastases was able to identify subgroups of patients at significantly different risk for further axillary involvement.
  
  
  CONCLUSIONS
  Patients with the most favorable combination of predictive factors still have no less than 13% risk for nonsentinel lymph node metastases and should be offered completion ALND outside of clinical trials of SLN biopsy without back-up axillary clearing.
authors.affiliation: Department of Pathology and Laboratory Medicine, European Institute of Oncology, University of Milan School of Medicine, Milan, Italy. giuseppe.viale@ieo.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Viale
authors.forename: Eugenio
authors.initials: E
authors.lastname: Maiorano
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Pruneri
authors.forename: Mauro G
authors.initials: MG
authors.lastname: Mastropasqua
authors.forename: Stefano
authors.initials: S
authors.lastname: Valentini
authors.forename: Viviana
authors.initials: V
authors.lastname: Galimberti
authors.forename: Stefano
authors.initials: S
authors.lastname: Zurrida
authors.forename: Patrick
authors.initials: P
authors.lastname: Maisonneuve
authors.forename: Giovanni
authors.initials: G
authors.lastname: Paganelli
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mazzarol
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy