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

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed cancer that overexpresses HER2/neu, measured 3+ by immunohistochemistry or positive by fluorescence in situ hybridization * Recurrent or metastatic disease * Meets 1 of the following criteria for measurable or evaluable disease: * Unidimensionally measurable disease at least 20 mm by conventional techniques OR at least 10 mm by spiral CT scan * Evaluable disease, defined as a lesion on physical examination or imaging study that can be assessed as to changes in size but cannot be clearly measured in 1 dimension (e.g., pleural effusions, ascites, or bone disease) * No carcinomatous meningitis or untreated/uncontrolled metastatic brain parenchymal disease * Prior controlled brain parenchymal disease allowed provided at least 8 weeks since prior therapy AND no symptomatic progression off corticosteroids PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 Life expectancy * Not specified Hematopoietic * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 Hepatic * ALT and AST ≤ 2.0 times upper limit of normal (ULN) * Alkaline phosphatase ≤ 2.0 times ULN * Bilirubin ≤ 1.3 mg/dL * No known chronic liver disease (i.e., chronic active hepatitis or cirrhosis) Renal * Creatinine ≤ 2.0 mg/dL Cardiovascular * Ejection fraction ≥ lower limit of normal by MUGA * No uncontrolled or significant cardiovascular disease * No myocardial infarction within the past 6 months * No ischemic heart disease requiring medication * No congestive heart failure Pulmonary * No uncontrolled or significant pulmonary disease Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective barrier contraception during and for 3 months after study participation * No active unresolved infection PRIOR CONCURRENT THERAPY: Biologic therapy * Prior trastuzumab (Herceptin®) allowed * No concurrent filgrastim (G-CSF) or sargramostim (GM-CSF) to support blood counts * No other concurrent anticancer biologic agents Chemotherapy * Prior chemotherapy for metastatic disease allowed * At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas) and recovered * No concurrent anticancer chemotherapy Endocrine therapy * See Disease Characteristics Radiotherapy * At least 4 weeks since prior radiotherapy and recovered Surgery * More than 2 weeks since prior major surgery Other * At least 7 days since prior antibiotics * No concurrent parenteral antibiotics * No other concurrent anticancer agents * No other concurrent investigational drugs * No concurrent therapeutic anticoagulation with warfarin * Concurrent mini-dose warfarin (1 mg/day) for prophylaxis of central venous catheter thrombosis allowed