Tinzaparin in Treating Patients With Metastatic Kidney Cancer That Cannot Be Removed By Surgery

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed renal cell carcinoma of clear cell histology * Tumors of mixed histology eligible if ≥ 50% of tumor has clear cell histology * No nonclear cell histologies, collecting duct tumors, oncocytomas, or transitional cell tumors * Metastatic and unresectable disease that is clinically extending beyond the regional lymph nodes (histological confirmation not required) * Patients who are inoperable for their primary tumor representing the sole site of disease are ineligible * Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 2 cm by conventional techniques OR ≥ 1 cm by spiral CT scan * No known brain metastases PATIENT CHARACTERISTICS: * Expected survival \> 2 months * CALGB (ECOG/ZUBROD) performance status (PS) 0-2 OR Karnofsky PS 60-100% * Hemoglobin ≥ 10 g/dL * Platelet count ≥ 100,000/mm\^3 * Bilirubin ≤ 1.5 times upper limit of normal (ULN) * AST/ALT ≤ 1.5 times ULN * Creatinine ≤ 1.5 times ULN * INR ≤ 1.5 times control value * PTT \< 1.5 times control value * Negative pregnancy test * Fertile patients must use effective contraception * Patients must be able to receive subcutaneous injections at home * No other primary malignancy in the past 5 years other than basal cell carcinoma or carcinoma in situ of the cervix that has been curatively treated and is associated with a less than 30% risk of relapse in the next 5 years * No signs or symptoms of bleeding within 4 the past weeks * No known bleeding diathesis or high risk for bleeding due to any condition, including trauma within the past 4 weeks, active current bleeding, or hemorrhagic stroke or intraocular bleeding within the past 6 months * No active thromboembolism highly likely to require anticoagulation during the study period * No known or suspected history of type II heparin-induced thrombocytopenia * No allergy or hypersensitivity to heparin, tinzaparin sodium, pork products, sulfite, or benzyl alcohol * No uncontrolled severe intercurrent illness, including ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements * No uncontrolled arterial hypertension, history of gastrointestinal ulceration, and/or bleeding in the past 4 weeks * No diabetic retinopathy or history of retinal hemorrhage * Not pregnant or nursing * HIV-positive patients are allowed PRIOR CONCURRENT THERAPY: * No treatment with anticoagulation lasting \> 1 month in the past 6 months * No anticoagulation, including treatment with a low molecular weight heparin, at any time within the past month * More than 4 weeks since prior surgery, radiation therapy, immunotherapy, or chemotherapy * Recovered from prior therapy * No other concurrent investigational agents * No other concurrent anticoagulation therapy, including oral anticoagulants, thrombolytic agents, or any form of heparin * Concurrent antiplatelet agents allowed * No spinal or epidural puncture, anesthesia, or post-operative indwelling epidural catheters within the past 48 hours * No other concurrent anticancer agents or therapies * No concurrent sex hormones except for postmenopausal hormone replacement * No concurrent chemotherapy or immunotherapy * No concurrent palliative radiotherapy * Concurrent urgent use of corticosteroids allowed