Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed diffuse large B-cell lymphoma, meeting criteria for 1 of the
following:

- Relapsed after prior high-dose chemotherapy with stem cell support

- Relapsed after prior chemotherapy, including at least 1 prior standard
non-Hodgkin's chemotherapy regimen, but not a candidate for high-dose
chemotherapy with stem cell support

- Measurable disease

- At least 1 bidimensionally measurable lesion at least 1.5 cm by CT scan

- No primary or secondary CNS lymphoma

- No HIV-related lymphoma

- No known brain metastases

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- ECOG 0-2 OR

- Karnofsky 60-100%

Life expectancy

- More than 3 months

Hematopoietic

- Hemoglobin at least 9 g/dL

- Absolute neutrophil count at least 1,000/mm^3

- No colony-stimulating factors within 4 weeks before obtaining this result

- Platelet count at least 50,000/mm^3

- No platelet transfusion within 4 weeks before obtaining this result

Hepatic

- Bilirubin no greater than 2 times upper limit of normal (ULN)

- AST and ALT no greater than 2.5 times ULN

- No active hepatitis B or C viral infection

Renal

- Creatinine no greater than 2 times ULN OR

- Creatinine clearance at least 60 mL/min

Cardiovascular

- No myocardial infarction within the past 6 months

- No evidence of acute ischemia or new conduction system abnormalities on EKG

- No symptomatic congestive heart failure

- No unstable angina pectoris

- No cardiac arrhythmia

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- Sodium greater than 130 mEq/L

- HIV negative

- No ongoing or active infection

- No other concurrent uncontrolled illness that would preclude study participation

- No psychiatric illness or social situation that would preclude study compliance

- No prior allergic reaction attributable to compounds of similar chemical or
biological composition to bortezomib

PRIOR CONCURRENT THERAPY:

Biologic therapy

- See Disease Characteristics

- See Chemotherapy

- At least 4 weeks since prior immunotherapy

Chemotherapy

- See Disease Characteristics

- More than 4 weeks since prior chemotherapy

- More than 12 weeks since prior high-dose chemotherapy with hematopoietic stem cell
support

Endocrine therapy

- Not specified

Radiotherapy

- More than 4 weeks since prior radiotherapy

- No concurrent radiotherapy

Surgery

- More than 4 weeks since prior major surgery unless fully recovered

Other

- Recovered from prior therapy

- No other concurrent investigational agents

- No other concurrent investigational or commercial agents or therapies to treat the
malignancy