ERBB2 and breast cancer: Two large retrospective studies from Japan and Korea found no difference in overall survival between early-stage HR positive HER2-low and HER2-negative patients [10, 18] On the other hand, a recently published study of early-stage HR positive breast cancer found that while HER2-low status was not associated with recurrence free survival overall, there was a trend towards increased risk of recurrence specifically among those with lobular histology and HER2-low disease [8].