Key clinical point: In patients with human epidermal growth factor 2 (HER2)-positive early breast cancer, trastuzumab emtansine vs. trastuzumab is associated with longer invasive disease-free survival (DFS) regardless of the type of neoadjuvant chemotherapy (NACT) received.
Major finding: Trastuzumab emtansine was associated with longer invasive DFS vs. trastuzumab in high-risk patients (hazard ratio [HR], 0.50; 95% confidence interval [CI], 0.39-0.64), in patients who received anthracycline-based NACT (HR, 0.51; 95% CI, 0.38-0.67), and in those who received nonanthracycline-based NACT (HR, 0.43; 95% CI, 0.22-0.82).
Study details: This is a subgroup analysis of the KATHERINE trial comparing trastuzumab emtansine with trastuzumab in 1,486 HER2-positive patients with early breast cancer.
Disclosure: This study was funded by F. Hoffmann-La Roche Ltd. The authors received consulting fees, speaker bureau fees, honoraria, educational support, research funding, travel expenses, royalties from, and/or owned stocks in various organizations outside this work. Dr. Boulet was an employee of Parexel International GmbH contracted by F. Hoffmann-La Roche Ltd. Dr. Liu, Dr. Tesarowski, Dr. Lam, Dr. Song, and Dr. Smitt were/are employees of Genetech and/or owned stocks in Roche. All other authors declared no conflicts of interest.
Source: Mamounas EP et al. Ann Oncol. 2021 Apr 28. doi: 10.1016/j.annonc.2021.04.011.