A decision aid for predicting non-sentinel node involvement in women with breast cancer and at least one positive sentinel node

Background: Several clinical trials are re-evaluating the management of the axilla after sentinel node (SN) biopsy. Approximately 50–70% of patients with positive SN have no further nodal involvement. Estimates of the risk of non-sentinel node (NSN) involvement would aid decisions regarding further axillary surgery. Methods: Clinical and pathological variables for 82 breast cancer patients with metastasis to at least one SN, were used to find independent predictors of the status of NSNs. Results: NSN metastases were found in 46.3% of patients. In a regression model patient age, proportion of SN replaced by metastasis and number of SNs were independent predictors of NSN status. Conclusion: Data available after SN biopsy allow estimation of the risk of NSN metastases among patients with positive SNs. Individualised estimates of the risk of NSN involvement may facilitate discussions regarding the trade off between the likely benefits of further axillary surgery and the morbidity of this procedure.