title: Prospective multicenter comparison of models to predict four or more involved axillary lymph nodes in patients with breast cancer with one to three metastatic sentinel lymph nodes.
abstract: OBJECTIVE
  Three models have been developed to predict four or more involved axillary lymph nodes (ALNs) in patients with breast cancer with one to three involved sentinel lymph nodes (SLNs). Two scores were developed by Chagpar et al (Louisville scores excluding or including method of detection), and a nomogram was developed by Katz et al. The purpose of our investigation was to compare these models in a prospective, multicenter study.
  
  
  METHODS
  Our study involved a cohort of 536 patients having one to three involved SLNs who underwent ALN dissection. We evaluated the area under the receiver operating characteristic curve (AUC), calibration (for the Katz nomogram only), false-negative (FN) rate, and clinical utility of the three models. Results were compared with the optimal logistic regression (OLR) model that was developed from the validation cohort.
  
  
  RESULTS
  Among the 536 patients, 57 patients (10.6%) had > or = four involved ALNs. The AUC for the Katz nomogram was 0.84 (95% CI, 0.81 to 0.86). The Louisville score excluding method of detection was 0.75 (95% CI, 0.72 to 0.78). The Louisville score including method of detection was 0.77 (95% CI, 0.74 to 0.79). The FN rates were 2.5% (eight of 321 patients), 1.8% (two of 109 patients), and 0% (zero of 27 patients) for the Katz nomogram and the Louisville scores excluding and including method of detection, respectively. The Katz nomogram was well calibrated. Optimism-corrected bootstrap estimate AUC of the OLR model was 0.86. Using this result as a reasonable target for an external model, the performance of the Katz nomogram was remarkable.
  
  
  CONCLUSIONS
  We validated the three models for their use in clinical practice. The Katz nomogram outperformed the two other models.
authors.affiliation: Department of Obstetrics and Gynecology, Hôpital Tenon, Paris, France.
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Werkoff
authors.forename: Eric
authors.initials: E
authors.lastname: Lambaudie
authors.forename: Eric
authors.initials: E
authors.lastname: Fondrinier
authors.forename: Jean
authors.initials: J
authors.lastname: Levêque
authors.forename: Fréderic
authors.initials: F
authors.lastname: Marchal
authors.forename: Michele
authors.initials: M
authors.lastname: Uzan
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Barranger
authors.forename: François
authors.initials: F
authors.lastname: Guillemin
authors.forename: Emile
authors.initials: E
authors.lastname: Darai
authors.forename: Serge
authors.initials: S
authors.lastname: Uzan
authors.forename: Gilles
authors.initials: G
authors.lastname: Houvenaeghel
authors.forename: Roman
authors.initials: R
authors.lastname: Rouzier
authors.forename: Charles
authors.initials: C
authors.lastname: Coutant
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D015233:Models, Statistical; D049451:Nomograms; D021701:Sentinel Lymph Node Biopsy