Alemtuzumab and Combination Chemotherapy in Treating Patients With Newly Diagnosed Stage II, Stage III, or Stage IV T-Cell Non-Hodgkin's Lymphoma

RATIONALE: Monoclonal antibodies, such as alemtuzumab, 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. 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 growing. Giving alemtuzumab together with combination chemotherapy may kill more cancer cells. PURPOSE: This phase I/II trial is studying the side effects and best dose of alemtuzumab when given together with combination chemotherapy and to see how well they work in treating patients with newly diagnosed aggressive stage II, stage III, or stage IV T-cell non-Hodgkin's lymphoma.