ASO Author Reflections: Effect Sizes of Whole Breast Radiotherapy and Systemic Therapies on Regional Recurrence Incidence in Breast Cancer Patients

Excerpt

Twenty years’ experience in practicing sentinel lymph node biopsy (SLNB) in breast cancer patients demonstrates that residual axillary tumor burden is not synonymous with disease recurrence over time. While meta-analyses have reported a false-negative rate (FNR) for SLNB between 5 and 7%, the reported regional recurrence (RR) rate in node-negative patients is much lower (0.3–0.6%).1 Moreover, landmark randomized controlled trials (RCTs) in patients who do have a tumor-positive SLNB but do not undergo completion axillary lymph node dissection (ALND) show that these patients will also rarely develop axillary recurrences despite an almost 30% chance of having residual positive lymph nodes.2 Apart from an National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol B-04-like self-limiting phenomenon that we recently demonstrated in a study in SLNB N0 patients who had undergone ablative surgery without receiving further additional treatment and had a RR risk of only 2%,3 adjuvant radiotherapy (RT) and systemic treatments are factors that temper the growth of metastases in the axilla. In the present study, we aimed to quantify the effects of whole-breast RT and systemic treatments on the RR incidence in a large-population-based cohort of SLN N0 breast cancer patients.4 …