Reappraisal of internal mammary node metastases as a prognostic factor in patients with breast cancer.

Clinical, histologic, and biologic prognostic factors were examined in 144 patients with invasive breast cancer. It was determined whether variable prognostic factors, especially internal mammary lymph node metastases, would serve as a basis for the prognosis of breast cancer. In a univariate study, overall survival was significantly correlated with tumor size, axillary lymph node status, axillary and internal mammary lymph node metastases, and DNA ploidy status. Especially among patients with one to three positive axillary nodes, survival in case of internal mammary involvement were significantly lower than without internal mammary involvement. In a multivariate study, only axillary and internal mammary lymph node metastases were recognized as important, independent prognostic factors of survival, but neither axillary lymph node status nor DNA ploidy status appeared as important prognostic factors. It was concluded that internal mammary lymph node metastases is additional prognostic factor, especially in patients with one to three positive axillary nodes. Because axillary and internal mammary lymph node metastases could not be predicted from their clinical assessment, axillary lymph node dissection and biopsy of internal mammary nodes may be a useful staging procedure for these patients.