Lymph node metastasis in breast cancer: common prognostic markers lack predictive value.

Abstract

The purpose of this study was to determine whether routine biologic tumor markers can predict lymph node status. The authors attempted to discover whether predictors of axillary lymph node metastasis based on biologic characteristic of primary breast cancers exist. Eight hundred and fifty-one patients with invasive breast cancer who underwent surgical treatment, including axillary lymph node dissection, at a tertiary referral center were studied. Univariate and multivariate analysis were performed on prospectively gathered data from a breast cancer registry, including pathology, site of primary lesion in the breast, estrogen and progesterone receptor status, DNA index, S-phase fraction, nuclear grade, and extensive intraductal component. Outcome was determined by (1) the presence of any lymph node metastasis and (2) the presence of 10 or more lymph node metastases. The only independent predictors of lymph node metastasis were primary tumor size and pathology. For predicting 10 or more metastases, only size and ER-negative status were independent predictors. These factors accounted for less than 20% of the regression, implying that more than 80% of lymph node metastases are not explained by the regression model. Lymph node metastases were seen in 8.3% of T1a, 15.3% of T1b, and 30.7% of T1c lesions. Biologic tumor markers are not reliable predictors of lymph node metastasis, except possibly for T1a lesions, therefore direct pathologic evaluation of lymph node status cannot be abandoned. Efforts to determine lymph node status through other methods such as sentinel lymph node biopsy are warranted.