Effect of lymphoscintigraphy drainage patterns on sentinel lymph node biopsy in patients with breast cancer

Background Sentinel lymph node (SLN) biopsy examination is an accepted method of staging breast cancer patients. SLN biopsy examination in patients with drainage to the internal mammary chain (IMC) nodes is controversial. Methods A prospective study of SLN biopsy examination followed by axillary dissection was analyzed to determine how surgeons manage patients with IMC drainage and the rates of axillary SLN identification and positivity in these cases. Results Lymphoscintigraphy was performed in 2196 (53.2%) of the 4131 patients in this study. IMC drainage was noted in 80 patients (3.6%). An axillary SLN was identified in 29 of the 40 patients with IMC drainage alone (72.5%). The rate of finding a positive axillary lymph node did not differ based on the lymphoscintigraphic pattern (P = .470). Conclusions Most surgeons do not perform IMC SLN biopsy procedures. Even when lymphoscintigraphy shows isolated drainage to IMC nodes, axillary SLNs usually are identified. Lymphoscintigraphy therefore has limited usefulness.