Node-related factors and survival in node-positive breast carcinomas

The number of positive lymph nodes (+LNs) is the only node-related prognostic factor recognized by the American Joint Committee TNM system for breast cancer. In this study, we evaluated additional node-related prognostic factors in node-positive breast carcinomas. One hundred and thirty-four patients with infiltrating ductal carcinomas and axillary +LNs, who had been treated with modified radical mastectomy, were analyzed. Metastatic lymph nodes were evaluated for traditional prognostic factors, i.e., the number of involved nodes and the extranodal extension, but also for a variety of other node-related characteristics, such as nodal tumor burden and maximum size of tumor deposits, necrosis, stromatogenesis, extranodal vascular involvement, and nodal matting. The results reaffirmed the prognostic significance of metastasis in 1-3 vs. 4-7 axillary lymph nodes and, in addition, revealed the importance of 4 +LNs as a cut-off point for breast tumor aggressiveness, given that survival curves for 4-7 vs. >7 +LNs were indifferent. Interestingly, nodal tumor burden, when extensive, was statistically an adverse prognostic factor. Prognosis was equally poor if metastases to regional nodes showed extensive nodal necrosis or extensive nodal stromatogenesis, if there was extranodal spread, extranodal vascular involvement, or if the axillary +LNs were matted. In multivariate analysis, intranodal necrosis and extranodal vascular involvement were the only node-related features with a significant and independent prognostic function. Node-related pathological features in node-positive breast carcinomas are important in determining prognosis. Intranodal necrosis and extranodal tumor emboli should be considered, in parallel with the number of +LNs, in subsequent treatment design.