Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed follicular lymphoma

- Grade 1, 2, 3a, or 3b disease by WHO staging system

- CD20-positive by immunohistochemistry

- Previously untreated disease OR meets 1 of the following criteria for response to
prior treatment:

- Chemotherapy-resistant disease

- Relapsed or progressive disease

- Stable disease

- At least 12 weeks since prior systemic treatment

- At least 1 bidimensionally measurable lesion ≥ 11 mm by CT scan or MRI

- No transformation to high-grade lymphoma secondary to low-grade follicular lymphoma

- No prior or current CNS disease (i.e., CNS lymphoma or lymphomatous meningosis) NOTE:
A new classification scheme for adult non-Hodgkin's lymphoma has been adopted by PDQ.
The terminology of "indolent" or "aggressive" lymphoma will replace the former
terminology of "low", "intermediate", or "high" grade lymphoma. However, this
protocol uses the former terminology.

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- WHO 0-2

Life expectancy

- Not specified

Hematopoietic

- Not specified

Hepatic

- Not specified

Renal

- Not specified

Cardiovascular

- Ejection fraction ≥ 50% by echocardiography or MUGA

Immunologic

- No acute or ongoing infection

- No HIV infection

- No active autoimmune disease

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for 12 months after
completion of the study treatment

- No uncontrolled diabetes mellitus

- No other medical condition that would preclude study participation

- No other malignancy except nonmelanoma skin cancer or adequately treated carcinoma in
situ of the cervix

- No other condition (e.g., geographic proximity) that would preclude study compliance
and follow-up

PRIOR CONCURRENT THERAPY:

Biologic therapy

- See Radiotherapy

- Prior rituximab allowed

Chemotherapy

- See Disease Characteristics

Endocrine therapy

- More than 4 weeks since prior regular administration of corticosteroids

- Dose equivalent to ≤ 20 mg/day prednisone allowed for conditions other than
lymphoma or lymphoma-related symptoms

- No concurrent corticosteroids for prevention or treatment of side effects except
acute life-threatening side effects

Radiotherapy

- Prior radiolabeled anti-CD20 therapy (administered alone or in combination with
cytostatic drugs) allowed provided patient has achieved partial or complete response
after the therapy

- At least 12 months since prior anti-CD20 therapy

Surgery

- Not specified

Other

- More than 30 days since prior systemic tumor therapy

- More than 30 days since prior participation in another clinical trial

- No other concurrent anticancer therapy