ESR1 and cancer: In their meta-analysis of over 12,000 patients, Lowery et al. outlined the importance of steroid hormone receptor and HER2 status in establishing the risk of LRR, with those with ER+/HER2− cancers being considered to have a lower relative risk of LRR compared to triple-negative (OR: 0.38) and HER2-positive (OR: 0.34) molecular phenotypes [33].