Removal of the internal mammary sentinel node in breast cancer

The aim of the study was to determine the evolution of patients with internal mammary chain (IMC) drainage whether the IMC-sentinel lymph node (IMC-SLN) was biopsied or not, as well as to determine the clinical implications of the biopsy of the IMC-SLN (IMC-SLNB) in patients with breast cancer and IMC drainage in the lymphoscintigraphy.

Eighty-two out of 914 patients included in a prospective database of sentinel node (9%) showed IMC drainage and were included in the study. Two groups were established depending on the IMC-SLN removal: group A (IMC-SLN were removed): 44 patients, mean age 48.8 years, mean follow-up, 35.8 months. Group B (IMC-SLN were not removed): 38 patients, mean age 54.5 years, mean follow-up, 33.5 months. Kaplan-Meier plots were used to determine the overall survival rates.

Group A: four patients showed only IMC drainage, six patients presented positive IMC-SLN, nodal staging changed in five patients, treatment changed in two patients and tumour node metastasis stage grouping changed in three patients. All patients are currently disease-free. Group B: two patients showed only IMC drainage, axillary-SLN were positive in 12 patients, one patient presented nodal axillary and breast recurrence as well as distant disease and one patient presented multiorganic disease. This last patient died. The overall survival rates were very similar in both the groups.

IMC-SLNB improves nodal staging in breast cancer but has little impact on adjuvant treatment. However, it should be performed to obtain results, which will determine in the future whether it improves survival rates or not.