Predictors of axillary lymph node metastases in patients with T1 breast carcinoma

BACKGROUND Axillary lymph node metastases (ALNM) are the most important predictor of survival in patients with T1 breast carcinoma. Due to a relatively low incidence of axillary metastasis in tumors ≤ 2 cm, the role of axillary lymph node dissection for these patients has been questioned. The purpose of this study was to determine the association between the incidence of ALNM and 11 clinical/pathologic factors by univariate and multivariate analysis. METHODS The authors reviewed data from 918 patients with T1 breast carcinoma who underwent level I/II axillary dissection between 1979 and July 1995. The association between the incidence of ALNM and 11 clinical/ pathologic factors (size, lymph/vascular invasion, nuclear grade, S-phase, ploidy, palpability, age, estrogen receptor status, progesterone receptor status, HER-2/neu, and histology) was analyzed by univariate and, when significant, by multivariate analysis. RESULTS Approximately 23% of the 918 patients with T1 breast carcinoma had ALNM. Multivariate analysis identified four factors as independent predictors of ALNM: lymph/vascular invasion (P 1 cm. See editorial counterpoint on pages 1856-61 and reply to counterpoint on pages 1862-4, this issue. Cancer 1997; 79:1918-22. © 1997 American Cancer Society.