Bendamustine Hydrochloride and Rituximab With or Without Bortezomib Followed by Rituximab With or Without Lenalidomide in Treating Patients With High-Risk Stage II, Stage III, or Stage IV Follicular Lymphoma

Inclusion Criteria (Induction): * Histologically confirmed (biopsy-proven) diagnosis of follicular B-cell non-Hodgkin lymphoma with no evidence of transformation to large cell histology * Patients having both diffuse and follicular architectural elements are eligible if the histology is predominantly follicular (i.e., ≥ 50% of the cross-sectional area) and there is no evidence of transformation to a large cell histology * Diagnostic confirmation (i.e., core needle or excisional lymph node biopsy) required if the interval since tissue diagnosis of low-grade malignant lymphoma is \> 24 months * Bone marrow biopsy alone not acceptable * Stage II, III, or IV AND grade 1, 2, or 3a disease * Must meet criteria for High Tumor Burden (higher risk) as defined by either the Groupe D'Etude des Lymphomes Follicularies (GELF) criteria OR the follicular lymphoma international prognostic index (FLIPI) as defined below: * Patient must meet ≥ 1 of the following GELF criteria: * Nodal or extranodal mass ≥ 7 cm * At least 3 nodal masses \> 3.0 cm in diameter * Systemic symptoms due to lymphoma or B symptoms * Splenomegaly with spleen \> 16 cm by CT scan * Evidence of compression syndrome (e.g., ureteral, orbital, gastrointestinal) or pleural or peritoneal serous effusion due to lymphoma (irrespective of cell content) * Leukemic presentation (≥ 5.0 x 10\^9/L malignant circulating follicular cells) * Cytopenias (polymorphonuclear leukocytes \< 1.0 X 10\^…