The oncology injection is offered by us that is put into a muscle through a needle that's attached to a syringe (as an injection or shot). Trastuzumab is a prescription medication used to treat breast cancer and stomach cancer (gastric cancer). It is part of a group of medications called monoclonal antibodies. Trastuzumab injection products are used with other medications or after other medications have been used to treat a certain type of breast cancer that has spread to other parts of the body. It is a monoclonal antibody used to treat breast cancer and stomach cancer. Oncology injection is very useful.