DISEASE CHARACTERISTICS:

• Histologically confirmed* previously untreated follicular non-Hodgkin's lymphoma (NHL), meeting 1 of the following stage criteria:

  • Bulky stage II disease (i.e., at least 1 unidimensionally measurable mass ≥ 7 cm)
  • Stage III or IV disease NOTE: *Bone marrow biopsy as the sole means of diagnosis is not acceptable; fine needle aspiration is not acceptable
• WHO grade 1, 2, or 3a disease (i.e., > 15 centroblasts per high power field with centrocytes present)
• CD20-positive disease by flow cytometry or immunohistochemistry

• Measurable disease by physical examination or imaging studies

  • Tumor mass > 1 cm

  • Patients with only nonmeasurable disease are not eligible

    • The following are considered nonmeasurable disease:

      • Bone lesions
      • Ascites
      • Pleural or pericardial effusion
      • Lymphangitis cutis or pulmonis
      • Bone marrow lesions
• No known CNS involvement by lymphoma

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• Not specified

Hematopoietic

• Absolute neutrophil count ≥ 1,000/mm^3
• Platelet count ≥ 50,000/mm^3

Hepatic

• Bilirubin ≤ 2 times upper limit of normal (ULN)* NOTE: *Unless due to lymphoma or Gilbert's disease

Renal

• Creatinine ≤ 2 times ULN* NOTE: *Unless due to lymphoma

Immunologic

• No known HIV positivity

  • HIV negative (for patients with a history of IV drug abuse or any behavior associated with an increased risk for HIV infection)
• No known human anti-chimeric antibody positivity

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 3 months after completion of study treatment
• No other currently active* malignancy (including Waldenstrom's macroglobulinemia) except nonmelanoma skin cancer NOTE: *Patients who have completed prior anticancer therapy AND have < 30% risk for relapse are not considered to have a currently active malignancy

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No prior immunotherapy (e.g., monoclonal antibody-based therapy) for NHL

Chemotherapy

• No prior chemotherapy for NHL
• No concurrent chemotherapy

Endocrine therapy

• More than 2 weeks since prior corticosteroids except as maintenance therapy for a non-malignant disease
• No concurrent hormonal therapy except steroids for adrenal failure OR hormones for non-disease-related conditions (e.g., insulin for diabetes)

• No concurrent dexamethasone or other steroidal antiemetics except for the following circumstances:

  • Acute grade 3 or 4 monoclonal antibody-associated infusion reaction not responsive to transient discontinuation of antibody infusion or acetaminophen and diphenhydramine
  • Retreatment after an infusion reaction

Radiotherapy

• No prior radiotherapy for NHL

Surgery

• Not specified