Pathologic features associated with nonsentinel lymph node metastases in patients with metastatic breast carcinoma in a sentinel lymph node

BACKGROUND. To the authors' knowledge it has not yet been determined which patients with primary breast carcinoma and an axillary sentinel lymph node (SN) metastasis have additional metastases in nonsentinel lymph nodes. METHODS, Pathologic features of the primary breast carcinoma and its SN met astasis were examined in 194 patients and correlated with the tumor status of the non-SNs in the same axillary basin. Two-level cytokeratin immunohist ochemistry was applied to the Sh's and to non-SNs of cases that were negati ve by standard hematoxylin and eosin examination. RESULTS, Lymph node staging based on SN findings, size of the primary tumor , and presence of peritumoral lymphatic vascular invasion (LVI) were associ ated with non-SN metastasis. The majority (63%) of the 101 patients with SN macrometastases had non-SN metastases. Extranodal hilar tissue invasion in conjunction with SN involvement also was strongly associated with non-SN m etastasis (P = 0.0001) but was present in only 65% of patients (35 of 54 pa tients) with non-SN macrometastases. Approximately 26% of patients (24 of 9 3 patients) with SN micrometastases (less than or equal to 2.0 mm) had non- SN metastases; among these patients only primary tumor size and peritumoral LVI were correlated with non-SN metastasis. CONCLUSIONS, Detailed pathologic examination of the primary tumor and its S N metastasis may increase precision in the selection of patients for furthe r axillary surgery or radiation therapy. (C) 2000 American Cancer Society.