Quantifying the Impact of Axillary Surgery and Nodal Irradiation on Breast Cancer–Related Lymphedema and Local Tumor Control: Long-Term Results From a Prospective Screening Trial

PURPOSE: To independently evaluate the impact of axillary surgery type and regional lymph node radiation (RLNR) on breast cancer-related lymphedema (BCRL) rates in patients with breast cancer. PATIENTS AND METHODS: From 2005 to 2018, 1,815 patients with invasive breast cancer were enrolled in a lymphedema screening trial. Patients were divided into the following 4 groups according to axillary surgery approach: sentinel lymph node biopsy (SLNB) alone, SLNB+RLNR, axillary lymph node dissection (ALND) alone, and ALND+RLNR. A perometer was used to objectively assess limb volume. All patients received baseline preoperative and follow-up measurements after treatment. Lymphedema was defined as a ≥ 10% relative increase in arm volume arising > 3 months postoperatively. The primary end point was the BCRL rate across the groups. Secondary end points were 5-year locoregional control and disease-free-survival. The 5-year locoregional control rates were similar for the ALND+RLNR, ALND-alone, SLNB+RLNR, and SLNB-alone groups (2.8%, 3.8%, 0%, and 2.3%, respectively). CONCLUSION: Although RLNR adds to the risk of lymphedema, the main risk factor is the type of axillary surgery used.