Sorafenib in Treating Patients at Risk of Relapse After Undergoing Surgery to Remove Kidney Cancer

DISEASE CHARACTERISTICS:

* Histologically confirmed renal cell carcinoma (RCC)

  * Clear cell or non-clear cell tumors allowed
  * Intermediate- or high-risk disease (Leibovich score 3 to 11)
* Must have undergone surgery for RCC at least 4 weeks but no more than 3 months prior to study entry

  * No evidence of residual macroscopic disease on post-operative CT scan after resection of RCC

PATIENT CHARACTERISTICS:

* WHO performance status 0-1
* WBC \> 3,400/mm³
* Platelet count \> 99,000/mm³
* Creatinine \< 2.5 times upper limit of normal (ULN)
* Liver function tests \< 1.5 times ULN
* Serum amylase \< 1.5 times ULN
* PT/INR \< 1.5 times ULN
* PTT \< 1.5 times ULN
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception during and for 9 months after completion of study treatment
* No cardiovascular conditions, including any of the following:

  * Cardiac arrhythmias requiring anti-arrhythmic medication

    * Beta-blockers and digoxin allowed
  * Symptomatic coronary artery disease or ischemia
  * Myocardial infarction within the past 6 months
  * NYHA class II-IV congestive heart failure
* No active clinically serious bacterial or fungal infection
* No known history of HIV infection
* No chronic hepatitis B or C
* No other prior malignancy except carcinoma in situ of the cervix or adequately treated basal cell carcinoma
* No uncontrolled hypertension

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* No prior treatment for RCC other than nephrectomy
* More than 30 days since prior and no other concurrent investigational therapy
* No concurrent medications that have adverse interactions with sorafenib tosylate including, but not limited to, any of the following:

  * Rifampin
  * Grapefruit juice
  * Ritonavir
  * Ketoconazole
  * Itraconazole
  * Hypericum perforatum (St John's wort)
* No concurrent bone marrow transplant or stem cell rescue
* No other concurrent drug that targets angiogenesis, especially VEGF or VEGF receptors (e.g., bevacizumab)
* No other concurrent drug that targets Ras-pathway or EGFR
* No other concurrent anticancer therapy (chemotherapy, immunotherapy, signal transduction inhibition, or hormonal therapy)
* Concurrent non-conventional therapies (e.g., herbs or acupuncture) and vitamin or mineral supplements allowed
* Concurrent bisphosphonates for prophylaxis of osteoporosis allowed