The positive sentinel lymph node biopsy- can we predict which patients will benefit from further surgery?

Introduction: Although sentinel lymph node biopsy (SLNB) is the gold standard for clinical and radiological negative axillae in breast cancer, the subsequent management of positive nodes is currently under scrutiny with the Z0011 trial publication causing much debate. Our aim was to determine whether there were any predictive factors in our cohort of patients that could assist in the decision of whether the patient required a further axillary lymph node clearance. Methods: A retrospective analysis of a prospectively maintained database of patients who underwent SLNB and their histology was performed. Univariate and multivariate analysis was performed to identify any predictive factors. Results: Our Breast Unit performed 457 SLNB over the three years. The mean age of patients was 61.9 years (range 31-89 years). Of these 457 SLNB, 122 (26.7%) were positive for metastatic involvement, and of these patients only 34% were found to have further lymph node involvement after axillary lymph node clearance (ALNC). Only 8% of our total patient cohort had non sentinel node involvement at completion ALNC. Using univariate analysis, lymphovascular invasion (p=0.009), grade (p=0.007) and size (p=0.006) were all significant predictors for having a positive ALNC. Conclusion: Only 8% of the total number of patients had an additional positive lymph node found in their completion axillary clearance. Our results add to this existing knowledge on the subject, and show that there are certain factors which should be carefully considered pre-operatively in order to help inform patient and surgeon choice regarding management of the axilla