RATIONALE: Drugs used in chemotherapy, such as cyclophosphamide, doxorubicin, and vincristine, work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. Colony-stimulating factors, such as pegfilgrastim, may increase the number of immune cells found in bone marrow or peripheral blood and may help the immune system recover from the side effects of chemotherapy. Monoclonal antibodies, such as rituximab, can block cancer growth in different ways. Some find cancer cells and kill them or carry cancer-killing substances to them. Others interfere with the ability of cancer cells to grow and spread. It is not yet known whether combination chemotherapy and pegfilgrastim is more effective when given with or without rituximab in treating non-Hodgkin lymphoma.

PURPOSE: This phase II trial is studying the side effects of giving pegfilgrastim and combination chemotherapy together with or without rituximab and to see how well it works in treating older patients with aggressive B-cell non-Hodgkin lymphoma.

OBJECTIVES:

• Determine the side effects of pegfilgrastim and cyclophosphamide, doxorubicin hydrochloride, vincristine, and prednisone (CHOP) with or without rituximab in older patients with aggressive B-cell non-Hodgkin lymphoma.
• Determine adherence to therapy regimens in these patients.
• Determine antitumor effectivity of immunochemotherapy.

OUTLINE: This is a multicenter study.

All patients receive prephase treatment comprising vincristine on day -6 and prednisone on days -6 to 0. Patients are then randomized to 1 of 2 treatment arms.

• Arm I (without rituximab): Patients receive pegfilgrastim subcutaneously (SC) on day 2 or 4 and CHOP comprising cyclophosphamide IV, doxorubicin hydrochloride IV, and vincristine IV on day 1, and oral prednisone on days 1-5. Treatment repeats every 2 weeks for up to 6-8 courses in the absence of disease progression or unacceptable toxicity.
• Arm II (with rituximab): Patients receive pegfilgrastim and CHOP for up to 6-8 courses as in arm I. They also receive rituximab (administered 2 hours before beginning CHOP) on day 1. Treatment with rituximab repeats every 2 weeks for up to 8 courses.

Patients with bulky disease or extranodal disease also undergo radiotherapy.

DISEASE CHARACTERISTICS:

• Diagnosis of CD20-positive B-cell non-Hodgkin lymphoma (NHL)

  • Confirmed by an excisional biopsy of a lymph node or by a sufficiently extensive biopsy of an extranodal involvement (if there is no lymph node involvement)
  • Results of the immunohistological analysis of expression of the CD20 antigen by lymphoma cells must be obtained

• Aggressive disease, including any of the following B-cell NHL

  • Stage III follicular lymphoma

  • Stage III follicular lymphoma and diffuse B-cell lymphoma

  • Lymphoblastic precursor B-cell lymphoma

  • Diffuse large B-cell lymphoma, including any of the following subtypes:

    • Centroblastic
    • Immunoblastic
    • Plasmablastic
    • Anaplastic large cell
    • T-cell rich B-cell lymphoma
    • Primary effusion lymphoma
    • Intravasal B-cell lymphoma
    • Primary mediastinal B-cell lymphoma

  • Mantle zone lymphoma

  • Burkitt or Burkitt-like lymphoma

  • Aggressive marginal zone lymphoma (monocytoid)

• All risk group allowed

  • Age adjusted IPI 0-3

• Previously untreated disease

PATIENT CHARACTERISTICS:

• ECOG performance status (PS) 0-2 OR Karnofsky PS 60-100%
• No other serious concurrent diseases

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics