Factors affecting nodal status in invasive breast cancer: a retrospective analysis of 623 patients.

With increasing numbers of early, screen-detected breast cancers and the emergence of sentinel-node biopsy, surgical management of the axilla is evolving. In recent years many authors have searched for favorable subcategories of tumors in which it may be possible to avoid axillary lymph node clearance. The aim of this study is to determine preoperative factors that might predict lymph node negative axillae. A retrospective analysis of 623 patients with invasive breast cancer was performed. A number of clinical and pathological variables were analyzed. Uni- and multivariate analysis was carried out to determine factors predictive for lymph node metastases. Age, tumor size, grade, histology and lymphovascular invasion were found to be independent predictors of nodal positivity but, contrary to other recent studies, we found no effect of ER/PR (estrogen-receptor/progesterone-receptor) or HER-2 status. The strongest predictor of lymph node metastases was tumor size >50 mm (OR 2.33), followed by the presence of lymphovascular invasion (OR 1.33). Our results could be used for preoperative counseling and planning axillary surgery in patients with invasive breast cancer. We propose that the predictive factors identified in this study could be used in combination with axillary ultrasound to selectively target patients for sentinel-node biopsy or to target the use of ultrasonographic assessment of the axilla. However, no consistent and reliable markers have been identified to predict patients that can safely avoid axillary surgery.