Chlorambucil Compared With Radiation Therapy in Treating Patients With Previously Untreated Stage III or Stage IV Follicular Lymphoma

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