Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed mantle cell lymphoma (at initial diagnosis)
nonrefractory to prior therapy or with no prior therapy

- No documented disease progression while receiving prior chemotherapy

- CD20 and CD5 positive

- Presence of clinically and/or radiologically documented disease

- At least 1 site of disease must be bidimensionally measurable

- Bone lesions not considered bidimensionally measurable

- Minimum indicator lesions must be:

- Lymph nodes at least 1.5 cm x 1.5 cm by physical exam or spiral CT scan OR

- Other nonnodal lesions at least 1 cm x 1 cm by MRI, CT scan, or physical
exam

- No known CNS involvement by lymphoma

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- ECOG 0-2

Life expectancy:

- At least 12 weeks

Hematopoietic:

- Absolute granulocyte count at least 1,500/mm3

- Platelet count at least 75,000/mm3

Hepatic:

- Bilirubin no greater than 1.5 times upper limit or normal (ULN)

- AST no greater than 2.5 times ULN

Renal:

- Creatinine no greater than 1.5 times ULN OR

- Creatinine clearance at least 60 mL/min

Cardiovascular:

- No clinically significant cardiac symptomatology

- If history of cardiac disease, cardiac ejection fraction greater than 50%

Pulmonary:

- No clinically significant pulmonary symptomatology

- If history of symptomatic pulmonary disease:

- FEV1, FVC, and TLC greater than 60% predicted

- DLCO greater than 50% predicted

Other:

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- Must be accessible for treatment and follow-up (i.e., no geographical limitations)

- No uncontrolled bacterial, fungal, or viral infection

- No other serious concurrent disease

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- No prior radioactive monoclonal antibody therapy

- Prior rituximab allowed

Chemotherapy:

- See Disease Characteristics

- No more than 2 prior chemotherapy regimens allowed

- Same chemotherapy combination given for first line and second line therapy considered
2 regimens

- At least 6 weeks since prior chemotherapy

- No prior high-dose chemotherapy and stem cell transplantation

- No other concurrent cytotoxic chemotherapy

Endocrine therapy:

- No concurrent corticosteroids

Radiotherapy:

- No prior radiotherapy to greater than 25% of functioning bone marrow

- At least 4 weeks since prior radiotherapy (except low-dose, non-myelosuppressive
radiotherapy) and recovered

- No concurrent radiotherapy to sole site of measurable disease

Surgery:

- At least 2 weeks since prior major surgery

Other:

- No other concurrent investigational anticancer agents