Lymphovascular invasion enhances the prediction of non-sentinel node metastases in breast cancer patients with positive sentinel nodes

Background: Fifty percent of patients with sentinel lymph node (SLN) metast ases have no metastatic disease in non-SLNs on axillary lymph node dissecti on (ALND). The goal of this study is to determine which patients have metas tatic disease limited to the SLN, and, therefore, may not require completio n ALND. Methods: Of the first 1000 patients undergoing SLN biopsy at Memorial Sloan -Kettering Cancer Center, using a combined blue dye and isotope technique, 231 (26%) had positive SLN. Of these, 206 underwent completion ALND. They a re the study group for this report. Results: The likelihood of non-SLN metastasis was inversely related to thre e clinicopathologic variables: tumor size less than or equal to 1.0 cm; abs ence of lymphovascular invasion (LVI); and SLN micrometastases (less than o r equal to 2 mm). None of 24 patients with all three predictive factors had non-SLN metastases, whereas 58% of patients with none of the factors had d isease in the non-SLN. Conclusion: patients with small breast cancers, no LVI, and SLN micrometast ases have a low risk of non-SLN metastases, and may not require completion ALND.