RATIONALE: Monoclonal antibodies such as rituximab can locate cancer cells and either kill them or deliver cancer-killing substances to them without harming normal cells. It is not yet known which rituximab regimen is more effective in treating indolent non-Hodgkin's lymphoma.

PURPOSE: This randomized phase III trial is studying two different schedules of rituximab and comparing them to see how well they work in treating patients with low tumor burden indolent stage III non-Hodgkin's lymphoma or stage IV non-Hodgkin's lymphoma.

OBJECTIVES:

Primary

• Compare the time to rituximab failure in patients with low tumor burden indolent non-Hodgkin's lymphoma treated with rituximab scheduled vs rituximab retreatment.

Secondary

• Compare the time to first cytotoxic therapy in patients treated with these regimens.
• Determine the rationale for beginning cytotoxic therapy, defined as chemotherapy, radiotherapy, or radioimmunotherapy, in patients treated with these regimens.
• Compare the toxic effects associated with these regimens in these patients.
• Correlate response and duration of response in these patients with the pharmacokinetics of these regimens.
• Compare the health-related quality of life, distress, psychological functioning, physical well-being, and functional well-being of patients treated with these regimens.
• Compare the impact of differential treatment response (delayed time to rituximab failure and/or time to first cytotoxic therapy) on quality of life, distress, and psychological functioning in patients treated with these regimens.
• Determine the physical and functional well-being of patients during treatment with these regimens.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to histologic subtype (follicular vs other), age (under 60 vs 60 and over), and the time from diagnosis (less than 1 year vs at least 1 year).

• Induction rituximab: Patients receive rituximab IV once a week for 4 weeks. Patients are re-evaluated 8 weeks after the completion of induction rituximab. Patients with a partial or complete response to induction rituximab are randomized to 1 of 2 treatment arms.
• Arm I (retreatment rituximab): Patients receive rituximab IV once a week for 4 weeks upon disease progression provided time to progression is more than 6 months.
• Arm II (scheduled rituximab): Patients receive a single dose of rituximab IV once every 13 weeks until disease progression and in the absence of unacceptable toxicity.

Quality of life is assessed at baseline, 3, 6, 12, 24, 36, 48 months, and within 4 weeks of rituximab failure.

Patients are followed at least annually for 15 years from study entry.

PROJECTED ACCRUAL: A total of 389 patients will be accrued for this study within 45 months.

DISEASE CHARACTERISTICS:

• Histologically confirmed non-Hodgkin's lymphoma, including 1 of the following:

  • Follicular grade 1 or 2
  • Small lymphocytic
  • Marginal zone (nodal)
  • Marginal zone (splenic)
  • Mucosa-associated lymphoid tissue (MALT)
• No evidence of transformation to a large cell histology
• Stage III or IV disease

• Must meet the following criteria for low tumor burden:

  • No nodal or extranodal mass at least 7 cm
  • Less than 3 nodal masses greater than 3 cm in diameter
  • No systemic symptoms or B symptoms
  • No splenomegaly greater than 16 cm by CT scan
  • No evidence of risk of compression of a vital organ (i.e., ureteral or epidural)
  • No leukemic phase with greater than 5,000/mm^3 circulating malignant cells

  • No cytopenias, defined as any of the following:

    • Platelet count less than 100,000/mm^3
    • Hemoglobin less than 10 g/dL
    • Absolute neutrophil count less than 1,500/mm^3

• At least 1 objective measurable disease parameter

  • Abnormal PET scans will not constitute evaluable disease unless verified by CT scan or other appropriate imaging

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-1

Life expectancy

• Not specified

Hematopoietic

• See Disease Characteristics
• Absolute neutrophil count at least 1,500/mm^3*
• Hemoglobin at least 10 g/dL*
• Platelet count at least 100,000/mm^3* NOTE: *Without growth factor and/or transfusion support

Hepatic

• Bilirubin no greater than 2 times upper limit of normal (ULN) OR direct bilirubin normal for patients with Gilbert's Syndrome
• AST/ALT no greater than 5 times ULN
• Hepatitis B surface antigen negative

Renal

• Creatinine no greater than 2 times ULN

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• HIV negative

• No uncontrolled active infection

  • Afebrile for at least 48 hours off antibiotics
• No other malignancy within the past 2 years except adequately treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix

PRIOR CONCURRENT THERAPY:

Biologic therapy

• See Radiotherapy
• No prior immunotherapy for lymphoma

Chemotherapy

• No prior chemotherapy for lymphoma
• No concurrent chemotherapy

Endocrine therapy

• Not specified

Radiotherapy

• No prior radiotherapy for lymphoma
• No concurrent radiotherapy
• No concurrent radioimmunotherapy

Surgery

• Not specified