Lenalidomide in Treating Patients With Advanced or Unresectable Kidney Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed renal cell carcinoma (RCC) * Advanced or unresectable RCC * Measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded) as ≥ 20 mm with conventional techniques OR ≥ 10 mm with spiral CT scan * No brain metastases * Brain metastases that have been treated with either radiotherapy or surgery and remain asymptomatic, with no active brain metastases, as shown by CT scan or MRI, for ≥ 6 months are allowed PATIENT CHARACTERISTICS: * ECOG performance status (PS) 0-1 OR Karnofsky PS 70-100% * Absolute neutrophil count ≥ 1,500/mm³ * Platelet count ≥ 100,000/mm³ * Creatinine ≤ 2.0 mg/dL * Bilirubin ≤ 1.5 mg/dL * AST and ALT ≤ 2.5 times upper limit of normal (ULN) (5 times ULN if hepatic metastases are present) * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No other malignancies within the past 5 years, except for treated basal cell or squamous cell carcinoma of the skin, carcinoma in situ of the cervix or breast, localized prostate cancer, or superficial bladder cancer * No history of allergic reactions attributed to compounds of similar chemical or biological composition to lenalidomide or thalidomide * No uncontrolled intercurrent illness including, but not limited to, any of the following: * Ongoing or active infection * Symptomatic congestive heart failure * Unstable angina pectoris * Cardiac arrhythmia * Psychiatric illness or social situation that would limit study compliance * No hepatitis A, B, or C positivity * No HIV positivity PRIOR CONCURRENT THERAPY: * See Disease Characteristics * No more than 1 prior systemic therapy for RCC (e.g., chemotherapy, hormonal therapy, immunotherapy) * At least 4 weeks since prior surgery, radiotherapy, hormonal therapy, chemotherapy, or immunotherapy and recovered * No prior lenalidomide * No other concurrent anticancer agents or treatments * No other concurrent investigational agents * No concurrent sargramostim (GM-CSF), radiotherapy, or thalidomide