Researchers at Mayo Clinic have found amplification of HER2, a known driver of some breast cancers, in a type of bladder cancer called micropapillary urothelial carcinoma (MPUC), has shown that the presence of HER2 amplification is associated with particularly aggressive tumors. These findings suggest that administering trastuzumab to MPUC patients with HER2 amplification could improve outcomes, just as it has for breast cancer. The study is published in Modern Pathology.