RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Radiation therapy uses high-energy x-rays to damage cancer cells. It is not yet known if chlorambucil is more effective than radiation therapy in treating follicular lymphoma.

PURPOSE: Randomized phase III trial to compare the effectiveness of chlorambucil with that of radiation therapy in treating patients who have stage III or stage IV follicular lymphoma that has not been previously treated.

OBJECTIVES:

• Compare the effect of chlorambucil vs involved-field radiotherapy on progression-free survival of patients with previously untreated stage III or IV follicular lymphoma.
• Compare the complete and partial remission rates and overall survival of patients treated with these regimens.
• Compare the toxicity of these regimens in these patients.
• Compare the quality of life of patients treated with these regimens.

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

• Arm I: Patients receive oral chlorambucil on days 1-5. Treatment repeats every 4 weeks for 6-8 courses in the absence of disease progression or unacceptable toxicity.
• Arm II: Patients undergo radiotherapy on days 1 and 3 (and days 15 and 17 for split course).

Quality of life is assessed at baseline, prior to course 3, 6, and 8 (arm I), and then at 4-6 weeks after study.

Patients are followed at 4-6 weeks, 3-4 months (arm I), 3 months and 6 months (arm II), 11, 12, 15, 18, and 21 months, and then every 6 months thereafter.

PROJECTED ACCRUAL: A total of 444 patients (222 per treatment arm) will be accrued for this study within 4 years.

• Drug: chlorambucil
• Radiation: radiation therapy

DISEASE CHARACTERISTICS:

• Diagnosis of follicular lymphoma

  • Stage III or IV disease
  • Grades I, II, or III
  • Previously untreated disease
• Nodal and extranodal sites
• Bidimensionally measurable disease by physical examination or diagnostic imaging
• No CNS or orbital non-Hodgkin's lymphoma localization

PATIENT CHARACTERISTICS:

Age:

• 18 and over (for patients at EORTC centers)
• 65 and over (for patients at HOVON centers)

Performance status:

• WHO 0-2

Life expectancy:

• Not specified

Hematopoietic:

• WBC at least 4,000/mm^3
• Platelet count at least 100,000/mm^3
• Hemoglobin at least 6.0 g/dL

Hepatic:

• Not specified

Renal:

• Not specified

Cardiovascular:

• No severe cardiac disease that would preclude study treatment

Pulmonary:

• No severe pulmonary disease that would preclude study treatment

Other:

• HIV negative
• No severe neurologic, psychiatric, or metabolic disease that would preclude study treatment
• No other prior malignancy except basal cell skin cancer or carcinoma in situ of the cervix

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• Not specified

Endocrine therapy:

• No concurrent systemic corticosteroids, including dexamethasone for nausea and vomiting palliation (inhalation and topical corticosteroids allowed)

Radiotherapy:

• No concurrent elective radiotherapy to an adjacent negative lymph node

Surgery:

• Not specified