GM-CSF With or Without Vaccine Therapy After Combination Chemotherapy and Rituximab as First-Line Therapy in Treating Patients With Stage II, Stage III, or Stage IV Diffuse Large B-Cell Lymphoma

RATIONALE: Drugs used in chemotherapy, such as cyclophosphamide, doxorubicin, vincristine, and prednisone, work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as rituximab, can block cancer growth in different ways. Some block the ability of cancer cells to grow and spread. Others find cancer cells and help kill them or carry cancer-killing substances to them. Colony-stimulating factors, such as GM-CSF, 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. Vaccines made from a person's cancer cells may help the body build an effective immune response to kill cancer cells. It is not yet known whether giving GM-CSF together with vaccine therapy is more effective than giving GM-CSF together with a placebo when given after combination chemotherapy and rituximab in treating diffuse large B-cell lymphoma. PURPOSE: This randomized phase III trial is studying GM-CSF and vaccine therapy to see how well they work compared to GM-CSF and placebo when given after combination chemotherapy and rituximab as first-line therapy in treating patients with stage II, stage III, or stage IV diffuse large B-cell lymphoma.

OBJECTIVES: Primary * Compare the 3-year disease-free survival of patients with high-intermediate- or high-risk bulky stage II or stage III or IV diffuse large B-cell lymphoma treated with sargramostim (GM-CSF) with or without autologous immunoglobulin idiotype-KLH conjugate vaccine (FavId®) after combination chemotherapy comprising cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab (CHOP-R). Secondary * Compare the 2-year disease-free survival, duration of response, time to progression, overall survival, and safety in patients treated with these regimens. * Estimate the rate of immune reactivity to FavId®. OUTLINE: This is a randomized, double-blind, placebo-controlled study. Patients are stratified according to risk score (3 \[high-intermediate\] vs 4 or 5 \[high\]). * Chemotherapy: Patients receive cyclophosphamide IV, doxorubicin hydrochloride IV, vincristine IV, and rituximab IV on day 1 and oral prednisone on days 1-5. Treatment repeats every 21 days for up to 8 courses in the absence of disease progression or unacceptable toxicity. * Sargramostim (GM-CSF) with or without autologous immunoglobulin idiotype-KLH conjugate vaccine (FavId®): Patients achieving complete remission (CR) or unconfirmed CR after chemotherapy and who have FavId® available are randomized to 1 of 2 treatment arms. * Arm I: Patients receive FavId® vaccine subcutaneously (SC) on day 1. Patients also receive sargramostim (GM-CSF) SC on days 1-4. * Arm II: Patients receive placebo SC on day 1 and GM-CSF SC as in arm I. In both arms, treatment repeats once a month for 6 months and then once every 2 months for 24 months (18 total vaccinations) in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed periodically for up to 2 years. PROJECTED ACCRUAL: A total of 480 patients will be accrued for this study.