Trastuzumab is used to treat metastatic (spread) breast cancer. It is effective against tumors that overexpress the HER2/neu protein.
As part of chemotherapy regimen for adjuvant treatment of lymph-node positive, HER2/neu protein positive breast cancer. Treatment of gastric (stomach) cancer.
It is not known whether or not trastuzumab may be effective in other cancers that may also have this HER-2/neu protein, including ovarian, colon, endometrial, lung, bladder, prostate, and salivary gland tumors.