DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed papillary renal cell cancer, meeting 1 of the following stage criteria:

  • M1 (metastatic disease)
  • M0 with unresectable primary tumor

• Prior resection of primary tumor allowed

  • Histological confirmation of at least 1 metastatic site of disease required if patients underwent nephrectomy

• Measurable disease

  • At least 1 unidimensionally measurable lesion
  • Soft tissue disease irradiated within the past 2 months is not considered measurable disease
  • Soft tissue disease irradiated more than 2 months ago must have progressed to be considered measurable with additional measurable disease outside the radiation field
• No prior or concurrent (treated or untreated) brain metastases

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• Zubrod 0-2

Life expectancy

• Not specified

Hematopoietic

• WBC at least 3,000/mm^3
• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3

Hepatic

• Bilirubin no greater than 1.5 times upper limit of normal (ULN)
• SGOT or SGPT no greater than 1.5 times ULN (5 times ULN if there is liver involvement by tumor)

Renal

• Creatinine no greater than 2 times ULN

Ophthalmic

• No known history of any of the following corneal diseases:

  • Dry eye syndrome
  • Sjögren's syndrome
  • Keratoconjunctivitis sicca
  • Exposure keratopathy
  • Fuch's dystrophy
• No other active disorders of the cornea

Gastrointestinal

• No gastrointestinal tract disease resulting in an inability to take oral medication
• No requirement for IV alimentation
• No active peptic ulcer disease
• Able to swallow and/or receive enteral medication via gastrostomy feeding tube
• No intractable nausea or vomiting

Other

• Not pregnant or nursing
• Fertile patients must use effective contraception
• No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated stage I or II cancer currently in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No prior immunotherapy

Chemotherapy

• No prior chemotherapy

Endocrine therapy

• Not specified

Radiotherapy

• See Disease Characteristics
• At least 21 days since prior radiotherapy and recovered

Surgery

• See Disease Characteristics
• At least 28 days since prior surgery and recovered
• No prior surgical procedure affecting absorption

Other

• No concurrent combination antiretroviral therapy for HIV-positive patients