Trastuzumab and Imatinib Mesylate in Treating Patients With Recurrent or Metastatic HER2/Neu-Expressing Cancer

RATIONALE: Monoclonal antibodies such as trastuzumab can locate tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells. Imatinib mesylate may stop the growth of tumor cells by blocking the enzymes necessary for their growth and by stopping blood flow to the tumor. Giving trastuzumab together with imatinib mesylate may kill more tumor cells. PURPOSE: This phase I trial is studying the side effects and best dose of imatinib mesylate when given together with trastuzumab in treating patients with recurrent or metastatic HER2/neu-expressing (producing) cancer.