Abstract P5-22-06: Less axillary lymph node dissections in patients with locally advanced breast cancer since implementation of the MARI-procedure
Authors: C Boersma, D Koopman-Kuin, J Van der Starre-Gaal, JH Korte, EMA Roeloffzen, AB Francken, EM Noorda
Journal: Cancer Research (2018)

Abstract Introduction Over the last years patients with locally advanced breast cancer are increasingly treated with neoadjuvant chemotherapy (NAC). This can lead to downstaging of the breast tumor, leading to less extensive surgery and can also impact axillary tumor burden. In multiple reported series downstaging of axillary lymphogenic metastasis has been reported to complete pathological response (pCR) in 20-42% of patients. Radioactive iodine seeds have been used to mark the axillary metastatic node (MARI-procedure). This node is selectively removed after NAC. The need for additional surgery or radiotherapy of the axilla depends on the postoperative pathological outcome. This study shows the results of implementation of the MARI-procedure and its impact on postoperative axillary treatment. Methods A retrospective analysis done on outcome of the MARI-procedure in consecutive patients from 2015 - 2017 treated with NAC for stage III breast cancer in a large teaching hospital. Patients' axillary status was determined pre-NAC by axillary ultrasonography, FNA and PET-scan. In these patients the metastatic lymph node was selectively marked with iodine seed. At surgery post-NAC the lymph node was removed. Adjuvant treatment was determined in the tumor board depending on the pathological result. Table 1 demonstrates the used algorithm for adjuvant axillary treatment. Descriptive statistics in terms of measured frequencies and central tendencies were used to describe the outcomes. Table 1: adjuvant axillary treatment algorithm FNA proven axillary lymph node metastasis N1 N2-3 pCR Residual tumor pCR Residual tumorNo axillary treatment Axillary radiotherapy Axillary radiotherapy ALND + axillary radiotherapy Results In total 50 consecutive patients were included and analyzed. Thirty one patients were staged cN1. Ten of these patients demonstrated a complete pathological response (ypN0) and did not receive any adjuvant axillary treatment. Sixteen patients had residual pathological tumour activity (ypN1) and received axillary radiotherapy. Five patients with residual disease underwent ALND (two patients ypN1, three patients ypN2). In the two patients staged ypN1, the algorithm was not followed due to progressive disease in the breast and the other because of occult axillary disease.Nineteen patients were staged cN2. Twelve of these patients had a complete pathological response (ypN0) and received axillary radiotherapy and seven patients had residual disease (ypN1 or ypN2) and treated with ALND. If ypN2 axillary radiotherapy was added. In total, 20% of patients did not receive any adjuvant axillary treatment, 56% received adjuvant axillary radiotherapy and 24% patients underwent ALND. Conclusion The number of patients with locally advanced breast cancer treated with ALND is obviously decreased since implementation of the MARI procedure after NAC. Hereby, one out of five patients could be spared any adjuvant axillary treatment. There is a need for follow up of long term results to assess recurrence risk and overall survival. Citation Format: Boersma C, Koopman-Kuin D, Van der Starre-Gaal J, Korte JH, Roeloffzen EMA, Francken AB, Noorda EM. Less axillary lymph node dissections in patients with locally advanced breast cancer since implementation of the MARI-procedure [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-22-06.