Sunitinib in Treating Patients With Metastatic Germ Cell Tumors That Have Relapsed or Not Responded to Treatment

DISEASE CHARACTERISTICS: * Histologically confirmed seminoma or nonseminoma germ cell tumors (GCT) * Refractory or relapsed disease * Metastatic disease * Progressive disease after prior cisplatin-based chemotherapy AND meets 1 of the following criteria for salvage therapy: * Not a candidate for potentially curative therapy * Received prior high-dose chemotherapy regimens * Declines potentially curative therapy (mediastinal GCT or primary refractory GCT) * Measurable disease\*, defined as 1 of the following: * At least 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan * Elevation of alpha-fetoprotein \> 15 ng/mL and/or elevation of human chorionic gonadotropin \> 2.2 mIU/L * NOTE: \*Patients with radiographically measurable disease only must have ≥ 1 site that has not undergone prior irradiation PATIENT CHARACTERISTICS: * Karnofsky performance status 70-100% * Absolute neutrophil count ≥ 1,500/mm³ * Platelet count ≥ 100,000/mm³ * Hemoglobin ≥ 9.0 g/dL * Creatinine ≤ 1.5 times upper limit of normal (ULN) * Bilirubin ≤ 1.5 times ULN * AST and ALT ≤ 2.5 times ULN (unless elevated liver function abnormalities due to underlying malignancy) * LVEF ≥ 50% by MUGA * No grade 3 hemorrhage within the past 4 weeks * None of the following within the past 6 months: * Myocardial infarction * Severe or unstable angina * Coronary or peripheral artery bypass graft * Symptomatic congestive heart failure * Cerebrovascular accident or transient ischemic attack * Pulmonary embolism * No prolonged QTc interval (i.e., QTc \> 450 msec for males and \> 470 msec for females) * No ongoing cardiac dysrhythmias ≥ grade 2 * No uncontrolled hypertension, defined as blood pressure \> 150/100 mm Hg despite optimal therapy * No active infection * No other severe acute or chronic medical or psychiatric condition or laboratory abnormality that would preclude study compliance, according to the study investigator * Not pregnant or nursing * Negative sonogram required to exclude pregnancy * Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: * See Disease Characteristics * No prior sunitinib malate * More than 4 weeks since prior major surgery and recovered * More than 4 weeks since prior radiotherapy and recovered * Concurrent palliative radiotherapy to metastatic lesion(s) allowed provided ≥ 1 measurable lesion has not been irradiated * No concurrent therapeutic doses of warfarin * Low-dose oral warfarin (up to 2 mg daily) for prophylaxis and treatment or heparin products at prophylactic or treatment doses allowed * No other concurrent investigational or approved anticancer therapies, including chemotherapy, biologic response modifiers, hormone therapy, or immunologic-based treatment * Concurrent participation in supportive care or nontreatment trials (e.g., quality-of-life or laboratory analyses) allowed