Epratuzumab and Rituximab in Treating Patients With Previously Untreated Follicular Non-Hodgkin Lymphoma

DISEASE CHARACTERISTICS:

Histologically* confirmed follicular non-Hodgkin lymphoma (NHL)

Previously untreated disease
WHO classification grade 1, 2, or 3a (> 15 centroblasts per high power field with centrocytes present) that is stage III, IV, or bulky (i.e., single mass ≥ 7 cm in any unidimensional measurement) stage II disease NOTE: *Bone marrow biopsies as the sole means of diagnosis are not acceptable, but they may be submitted in conjunction with nodal biopsies; fine-needle aspirates are not acceptable for diagnosis
Confirmed CD20 antigen expression by flow cytometry or immunohistochemistry

Measurable disease by physical examination or imaging studies

Any tumor mass > 1 cm is acceptable

No nonmeasurable disease only, including any of the following:

Bone lesions
Ascites
Pleural/pericardial effusion
Lymphangitis cutis/pulmonis
Bone marrow (involvement by NHL should be noted)
No known CNS involvement by lymphoma
Required to participate in companion FDG-PET imaging study CALGB 580701

PATIENT CHARACTERISTICS:

ECOG performance status ≤ 2
Absolute neutrophil count ≥ 1,000/μL
Platelet count ≥ 50,000/μL

Patients with HIV infection are eligible provided they meet the following criteria:

No evidence of coinfection with hepatitis B or C
CD4+ cell count ≥ 400/mm^3
No evidence of resistant strains of HIV
If not on anti-HIV therapy, HIV viral load < 10,000 copies HIV RNA/mL
If on anti-HIV therapy, HIV viral load < 50 copies HIV RNA/mL
No history of AIDS-defining conditions
Not pregnant or nursing
Fertile patients must use effective contraception during and for 3 months after completion of study therapy
No known Human Anti-Chimeric Antibody (HACA)-positivity

PRIOR CONCURRENT THERAPY:

No prior therapy for NHL including chemotherapy, radiotherapy, or immunotherapy (e.g., monoclonal antibody-based therapy)
More than 2 weeks since prior corticosteroids except for maintenance therapy for non-malignant disease

No concurrent dexamethasone or other steroids as antiemetics except for the following circumstances:

Treatment of acute infusion reactions according to institutional procedures
No concurrent hormonal therapy except steroids for adrenal failure OR hormones for non-disease-related conditions (e.g., insulin for diabetes)
No other concurrent chemotherapeutic agents