GM-CSF, Rituximab, and Combination Chemotherapy in Treating Patients With Previously Untreated Advanced Follicular Non-Hodgkin Lymphoma

DISEASE CHARACTERISTICS:

* Histologically confirmed follicular non-Hodgkin lymphoma

  * Grade 1-3a disease
  * Advanced disease
* Has undergone initial lymph node biopsy within the past 4 months
* At least 1 measurable lesion
* Bulky disease, as defined by the following GELF criteria:

  * Nodal or extranodal mass \> 7 cm in its greatest diameter
  * Involvement of ≥ 3 nodal sites (each with a diameter \> 3 cm)
  * B symptoms
  * Elevated serum LDH or β2-microglobulin
  * Splenic enlargement
  * Compression syndrome
  * Pleural and/or peritoneal effusion
* No transformation to high-grade follicular lymphoma (secondary to low-grade follicular lymphoma)
* No prior or concurrent CNS disease (i.e., CNS lymphoma or lymphomatous meningitis) NOTE: A new classification scheme for adult non-Hodgkin 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:

* ECOG performance status 0-1
* Life expectancy ≥ 6 months
* ANC ≥ 1,000/mm\^3\*
* Platelet count ≥ 100,000/mm\^3\*
* Hemoglobin ≥ 8.0 g/dL\*
* Total bilirubin ≤ 2.0 mg/dL\*
* AST ≤ 3 times upper limit of normal\*
* Serum creatinine ≤ 2.0 mg/dL
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception during and for 12 months after completion of study treatment
* No known HIV infection
* No active hepatitis B or C infection
* No serious underlying medical condition that would preclude study participation (e.g., ongoing infection, uncontrolled diabetes mellitus, gastric ulcer, active autoimmune disease, or heart failure)
* No known sensitivity or allergy to murine products
* No other prior or concurrent malignancies except nonmelanoma skin cancer or adequately treated in situ cervical cancer
* No other co-existing medical or psychological condition that would preclude study participation or ability to give informed consent NOTE: \*Unless abnormalities are related to lymphoma

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* No prior treatment for follicular lymphoma, including steroids or radiotherapy
* More than 4 weeks since prior corticosteroids unless administered at a dose equivalent to \< 20 mg/day of prednisone
* More than 28 days since prior major surgery (excluding lymph node biopsy)
* More than 30 days since prior treatment in a clinical trial