Do all patients with sentinel node metastasis from breast carcinoma need complete axillary node dissection?

Objective To determine the likelihood of nonsentinel axillary metastasis in the presence of sentinel node metastasis from a primary breast carcinoma. Summary Background Data Sentinel lymphadenectomy is a highly accurate techn ique for identifying axillary metastasis from a primary breast carcinoma. O ur group has shown that nonsentinel axillary lymph nodes are unlikely to co ntain tumor cells if the axillary sentinel node is tumor-free, but as yet n o study has examined the risk of nonsentinel nodal involvement when the sen tinel node contains tumor cells. Methods Between 1991 and 1997, axillary lymphadenectomy was performed in 15 7 women with a tumor-involved sentinel node. Fifty-three axillae (33.5%) ha d at least one tumor-involved nonsentinel node. The authors analyzed the in cidence of nonsentinel node involvement according to clinical and tumor cha racteristics. Results Only two variables had a significant impact on the likelihood of no nsentinel node metastasis: the size of the sentinel node metastasis and the size of the primary tumor. The rate of nonsentinel node involvement was 7% when the sentinel node had a micrometastasis (less than or equal to 2 mm), compared with 55% when the sentinel node had a macrometastasis (>2 mm). In addition, the rate of nonsentinel node tumor involvement in; creased with the size of the primary tumor. Conclusions If a primary breast tumor is small and if sentinel node involve ment is micrometastatic, then tumor cells are unlikely to be found in other axillary lymph nodes. This suggests that axillary lymph node dissection ma y not be necessary in patients with sentinel node micrometastases from T1/T 2 lesions, or in patients with sentinel node metastases from T1a lesions.