Since 2005, patients with early stage HER2-positive breast cancer have been treated with 1 year of adjuvant trastuzumab (an anti-HER2 antibody) as standard of care. However, results from the FinHer trial indicated that shorter durations of treatment might be equally efficacious. Against this background, the PHARE trial recruited over 3,380 HER2-positive patients with breast cancer and randomly assigned them to receive either 6 months or 1 year of adjuvant trastuzumab. When the data were presented at a Presidential Symposium Session at the ESMO annual symposium, noninferiority of the shorter trastuzumab treatment could not be shown. Lead author Xavier Pivot stated: “there was a trend favouring the standard 12-month treatment. However, there were significant differences in cardiac events favouring 6-month treatment.”