Pathologic findings from the national surgical adjuvant breast project. (Protocol no. 4). III. The significance of extranodal extension of axillary metastases

One hundred fifty-eight patients with axillary nodal metastases recovered from radical mastectomy specimens for operable, invasive breast cancer were divided into those in whom such metastases were confined within the node and those in whom one or more nodes manifested extranodal extension. The relationships of these patterns to 33 pathologic and seven clinical features of these cases were investigated by contingency table analysis. Statistically significant associations (p less than .05) between extranodal extension of such metastases and short-term treatment failure, as well as the presence of four or more involved nodes, infiltrating ductal NOS histologic tumor type, stellate tumor border, and nipple involvement, were found. When the metastases were confined to the node there was a significantly greater likelihood that the cancers were either medullary or tubular histologic types. Associations with severe cell reaction and a nuclear grade of 1 were also found, but appeared to reflect the high frequency of medullary carcinomas in this group. The results suggest that evaluation of extranodal extension of axillary nodal metastases in patients with breast cancer may represent an important prognostic discriminant.