- Histologic diagnosis of urothelial carcinoma (TCC or Squamous) that is either metastatic or locally recurrent and not curable by surgery or radiation therapy; patients must have HER2 overexpression as documented by ANY of the following: 1. 2+ or 3+ staining by immunohistochemistry, or 2. a positive FISH score defined as > 2 with the Vysis system or > 4 with the Ventana system, or 3. an elevated serum HER2 of > 16 ng/ml using the OSDI assay; please note: