Omitting Radiotherapy after Breast-Conserving Surgery in Luminal A Breast Cancer: The LUMINA Study.

The modern generation of trials evaluating the role of adjuvant radiation have turned to genomic profiling as a further risk stratification tool. The LUMINA trial by Whelan et al, published in the New England Journal of Medicine, applied Ki67 testing to identify those with luminal A disease and evaluated locoregional outcomes with Breast Conserving Surgery (BCS) and endocrine therapy (ET) alone. This paper was reviewed at the Canadian Association of General Surgeons' "Evidence-Based Reviews in Surgery" (EBRS) webinar series. Here, we present the EBRS panel's methodologic review and clinical commentary. The LUMINA study demonstrated very low rates of Local Recurrence (LR) in low-risk patients with luminal A biologic subtype treated with BCS and ET alone without radiation. While the LUMINA study was rigorously designed and executed, there are significant pragmatic limitations to the implementation of the proposed approach using their protocol. We advocate that there is no "one size fits all" approach to early ER+ breast cancer. Choice of treatment strategy should strongly consider patient goals and preferences, with need for incorporation of Quality of Life and patient-reported endpoints into future studies evaluating this population to help guide these nuanced decisions.