Combination Chemotherapy With or Without Thalidomide in Treating Patients With Multiple Myeloma

RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Thalidomide may stop the growth of cancer cells by stopping blood flow to the cancer. Peripheral blood stem cell transplant using stem cells from the patient or a donor may be able to replace immune cells that were destroyed by chemotherapy used to kill cancer cells. The donated stem cells may also help destroy any remaining cancer cells (graft-versus-tumor effect). It is not yet known whether chemotherapy followed by peripheral blood stem cell transplant is more effective with or without thalidomide in treating multiple myeloma. PURPOSE: This randomized phase III trial is studying giving combination chemotherapy with thalidomide to see how well it works compared with giving combination chemotherapy without thalidomide in treating patients with multiple myeloma.