Rituximab in Treating Patients With Follicular Non-Hodgkin's Lymphoma

RATIONALE: 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. It is not yet known whether giving rituximab over a short period of time is more effective than giving it over a long period of time in treating follicular non-Hodgkin's lymphoma. PURPOSE: This randomized phase III trial is studying rituximab to see how well it works when given over a short period of time compared to when given over a long period of time in treating patients with follicular non-Hodgkin's lymphoma.