Biopsies of the Internal Mammary Sentinel Lymph Nodes in Breast Cancer

Background: The aim of the present study was to report internal mammary sentinel lymph node (IM SLN) biopsy results and to review and discuss their impact on treatment and prognosis. Patients and methods: We retrospectively reviewed the data from 107 patients who underwent a biopsy of IM nodes after the IM SLN was visualised (in 16 patients, only the IM SLN was visualised) by preoperative lymphoscintigraphy after peritumoural and intra-mammary injections of 99mTc-human serum albumin nanocolloids. Results: In 9 out of 107 patients, exploration of the IM node chain was not successful. Seven (8.6%) of the 82 patients with axillary (Ax) and IM SLN visualisation had a pathologically positive (pN+) IM SLN; while, 3 (20%) of the 16 patients, in whom only the IM SLN could be visualised, had a pN+ IM SLN. Three patients with pN+ IM SLN status were administered chemotherapy and five patients underwent irradiation of the parasternal chain. However, the pN- IM SLN status of 16 patients argued against such irradiation. The pN+ IM SLN status also changed the pTNM stage in six patients, the Nottingham Prognostic Index score in five patients, and the percentages of relapse risk and/or of cancer-related death (based on “Adjuvant Online”) in six patients. Conclusions: An IM SLN biopsy can be safely performed and is recommended when lymphoscintigraphy reveals IM chain drainage. The pN+ IM SLN status can affect treatment decisions.