Predictors to assess non-sentinel lymph node status in breast cancer patients with sentinel lymph node metastasis.

The next step of sentinel lymph node biopsy (SLNB) in breast cancer is to determine which patients need axillary lymph node dissection (ALND) following a positive SLNB. A prospective database of 239 patients who underwent SLNB followed by complete ALND at Keio University Hospital from January 2001 to June 2005 was reviewed. A total of 131 patients with one or more positive sentinel lymph nodes (SLNs) were further analyzed. A univariate analysis showed a significant correlation between non-SLN involvement and lymphatic invasion, vascular invasion, number of tumor-involved SLNs, radioactivity of SLNs, and size of SLN metastasis (p = 0.0002, p = 0.004, p = 0.006, p = 0.04, p = 0.03, respectively). By multivariate analysis, lymphatic invasion and the number of tumor-involved SLNs remained significant predictors of non-SLN involvement. In breast cancer patients with a positive SLN, lymphatic invasion and the number of tumor-involved SLNs were both independent predictors of non-SLN involvement.