Summary

In 2005, data from 3 large randomized trials demonstrated that 1 year of trastuzumab treatment provided a statistically significant disease-free survival benefit compared with no trastuzumab in patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer [Piccart-Gebhart MJ et al. N Engl J Med 2005]. One of these studies, the Trastuzumab in Treating Women with Primary Breast Cancer [HERceptin Adjuvant (HERA); NCT00045032] trial, continued trastuzumab therapy to assess whether 2 years of treatment was superior to 1 year. This article provides an update of the HERA trial after 8 years of median follow-up.