RATIONALE: Interferon alfa may interfere with the growth of tumor cells. Interleukin-2 may stimulate a person's white blood cells to kill tumor cells. Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining interferon alfa and interleukin-2 with fluorouracil may kill any remaining tumor cells following surgery. It is not yet known whether combining interferon alfa and interleukin-2 with fluorouracil is more effective than observation after surgery for kidney cancer.

PURPOSE: Randomized phase III trial to compare the effectiveness of combining interleukin-2, interferon alfa, and fluorouracil to that of observation alone in treating patients who have undergone surgery for kidney cancer and are at high risk of relapse.

OBJECTIVES:

• Compare the effect of adjuvant combination therapy comprising interleukin-2, interferon alfa, and fluorouracil vs observation only on disease-free survival or overall survival of patients with renal cell carcinoma at high risk of relapse after radical surgery.
• Compare the quality of life of patients treated with these regimens.

OUTLINE: This is a randomized, multicenter study. Patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients receive interleukin-2 subcutaneously (SC) on days 3, 4, and 5 of weeks 1 and 4 and on days 1, 3, and 5 of weeks 2 and 3. Patients also receive interferon alfa SC once weekly during weeks 1 and 4 and 3 times weekly during weeks 2, 3, 5, 6, 7, and 8. Patients then receive fluorouracil IV on day 1 of weeks 5, 6, 7, and 8.
• Arm II (control arm): Patients receive no adjuvant treatment before disease progression.

Quality of life is assessed at baseline and at 2 and 6 months after randomization.

Patients are followed monthly for 3 months (arm I only), every 3 months for 1 year, every 6 months for 4 years, and then annually thereafter.

PROJECTED ACCRUAL: A total of 550 patients (275 per treatment arm) will be accrued for this study within 3 years.

DISEASE CHARACTERISTICS:

• Histologically confirmed primary renal cell carcinoma meeting 1 of the following criteria:

  • Stage T3b, T3c, or T4 tumor
  • Any pT stage and nodal status pN 1 or 2
  • Any pT stage and microscopic positive margins
  • Presence of any microscopic vascular invasion

• Underwent surgical resection of primary tumor within the past month

  • Removal of clinical N+ disease required

• No evidence of metastatic disease

• No evidence of macroscopic residual disease

PATIENT CHARACTERISTICS:

Age

• 75 and under

Performance status

• WHO 0-1

Life expectancy

• Not specified

Hematopoietic

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

Hepatic

• Liver function tests no greater than 1.25 times upper limit of normal (ULN)

Renal

• Creatinine less than 1.5 times ULN

Cardiovascular

• No myocardial infarction within the past 6 months
• No unstable angina pectoris

Other

• Not pregnant or nursing
• No prior or other concurrent malignancies that would preclude study therapy or comparisons
• No other concurrent illness that would preclude study therapy
• No concurrent active infections requiring antibiotic therapy

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No other concurrent immunotherapy

Chemotherapy

• No prior chemotherapy

Endocrine therapy

• No concurrent corticosteroids
• No concurrent hormonal therapy

Radiotherapy

• No prior radiotherapy

Surgery

• See Disease Characteristics
• No prior major organ allografts

Other

• No other concurrent investigational drugs, agents, or devices