title: Which prediction models best identify additional axillary disease after a positive sentinel node biopsy for breast cancer?
abstract: To determine which web-based model best identifies women at low risk of further axillary disease after a positive sentinel lymph node (SLN+) biopsy. 673 women with T1-2cN0M0 SNB+ breast cancer who underwent completion axillary dissection (AxD) were identified. A subgroup not eligible to avoid AxD as part of the Z0011 study was defined (Z0011 exclusion group). Predicted risk of further axillary disease was generated using seven web-based models. "Low risk" was defined as a ≤10% risk of further axillary disease. False negative ("low risk" prediction but AxD+) rates (FNRs), area under the receiver operating characteristic curve (AUC), and Brier score were determined for each model. 6 of 7 models identified "low risk" patients but FNRs ranged from 14 to 30%. The Stanford and Memorial Sloan-Kettering (MSKCC) models had the best FNRs. FNRs were lower with SLN micrometastasis (7-15%) and higher in the Z0011 exclusion group (21-41%). All models under-predicted further nodal disease in low risk patients and over-predicted in higher-risk patients. The Stanford and MSKCC models were able to identify women with SLN micrometastasis with a ≤10% FNR. Models were not able to accurately identify low risk women from a cohort that would have been excluded from Z0011.
authors.affiliation: British Columbia Cancer Agency-Vancouver Island Centre, Radiation Therapy Program, Victoria, BC, Canada. tberrang@bccancer.bc.ca
authors.forename: Tanya S
authors.initials: TS
authors.lastname: Berrang
authors.forename: Mary
authors.initials: M
authors.lastname: Lesperance
authors.forename: Pauline T
authors.initials: PT
authors.lastname: Truong
authors.forename: Caroline
authors.initials: C
authors.lastname: Walter
authors.forename: Allen H
authors.initials: AH
authors.lastname: Hayashi
authors.forename: Ivo A
authors.initials: IA
authors.lastname: Olivotto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D015331:Cohort Studies; D003198:Computer Simulation; D005260:Female; D006801:Humans; D020407:Internet; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008875:Middle Aged; D015233:Models, Statistical; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy