Cohort study of iodine seed-marking protocol for response-guided axillary treatment after systemic therapy for node-positive breast cancer

Most patients with clinically node-positive breast cancer receive primary systemic treatment (PST) followed by axillary lymph node dissection and/or locoregional radiation. A retrospective study at the Netherlands Cancer Institute-Antoni van Leeuwenhoek (Amsterdam) included 350 patients with limited axillary nodal disease who underwent PST. The study using the MARI protocol (‘marking the axillary lymph node with a radioactive seed’) found that after 49 months of follow-up, the 135 patient (39%) who experienced pCR to PST and received no further axillary treatment had an axillary recurrence rate of 0.7% (one patient) and excellent 5-year survival data. The authors conclude that using the MARI protocol should be considered for patients with node-positive breast cancer who experienced nodal pCR after PST.