Neoadjuvant Treatment as a Risk Factor for Variation of Upper Limb Lymph Node Drainage During Axillary Reverse Mapping in Breast Cancer: A Prospective Observational Study

Background/Alpha im: The Axillary Reverse Mapping technique in breast cancer, was adopted in order to minimize the risk of upper limb lymphedema. Currently, there is only limited evidence available regarding its oncological safety. The aim of this study was to evaluate the presence of upper limb nodes in surgical specimens following axillary lymphadenectomy, and its relative predictive relevance. Patients and Methods: All patients undergoing axillary lymphadenectomy were enrolled in the current prospective observational study. Indocyanine green was injected into the ipsilateral arm, followed by the standard axillary surgical procedure. Subsequently, the surgical specimens were examined in order to identify any resected upper limb nodes. Results: Out of 22 patients, 5 (22.7%) exhibited fluorescent nodes in the surgical specimen. At univariate analysis, these patients presented statistically significant differences in terms of neoadjuvant treatment, estrogen receptor (ER), progesterone receptor (PR), Ki67 index and position of fluorescent lymph nodes (p=0.021, p=0.033, p=0.002, p=0.049 and p=0.001, respectively). At multivariate analysis, neoadjuvant chemotherapy and Ki67 index were associated with the risk of resecting fluorescent nodes during a standard lymphadenectomy (p=0.005 and p=0.018, respectively). Conclusion: Axillary Reverse Mapping should be individually tailored for patients with advanced axillary breast cancer and those undergoing neoadjuvant treatment. Suspected metastases or upper limb nodes identified in unusual positions must always be resected.