Distribution of axillary node metastases by level of invasion. An analysis of 539 cases.

Five hundred and thirty-nine patients with carcinoma of the breast treated with total axillary dissection and with positive axillary nodes were evaluated. The total number of lymph nodes removed was 11,082, with an average of 20.5 nodes per patient. The average number of lymph nodes at the first level was 13.8, at the second level 4.5, at the third level 2.2. The average number of nodes was 20.7 in cases treated with Halsted mastectomy, 20.9 with total mastectomy and axillary dissection, 20.3 with quadrantectomy and axillary dissection. Of 3259 metastatic nodes, 64 were site of micrometastases; 797 were partially involved, 441 were totally involved and 1957 were site of metastases with extracapsular invasion. In 314 (58.2%) the first level only was involved, in 117 cases (21.7%) metastases were present at the first and second level, whereas in 88 cases (16.3%) all the three levels were sites of metastases. Only 20 cases showed skipping distribution. In 1.5% of the cases the first level was skipped by metastases, in 0.4% the first nodes of the first level are clear the chances that metastatic nodes are present at the second and third levels are negligible. When the nodes at the first level are positive, the chances that metastases are also present at the higher levels are of the order of 40.0%.