Thalidomide and Prednisone After Autologous Stem Cell Transplantation Multiple Myeloma

DISEASE CHARACTERISTICS: * Histologically confirmed multiple myeloma as evidenced by one of the following: * Biopsy of an osteolytic lesion or soft tissue tumor composed of plasma cells * Bone marrow aspirate and/or biopsy demonstrating at least 10% plasmacytosis * Bone marrow less than 10% plasma cells with at least 1 bony lesion and meets the M-protein criteria as below * Detectable serum M-component of IgG, IgA, IgD, or IgE at initial diagnosis OR * Urinary excretion of light chain (Bence Jones) protein at least 1.0 gm/24 hrs if only light chain disease (urine M-protein) was present at initial diagnosis * Previously treated with autologous stem cell transplantation after high-dose melphalan (200 mg/m\^2) within the past 60-100 days * Received transplantation within 1 year of the beginning of initial chemotherapy for multiple myeloma * No evidence of disease progression PATIENT CHARACTERISTICS: Age * 16 and over Performance status * ECOG 0-2 Life expectancy * At least 6 months Hematopoietic * No prior hereditary hypercoaguable disorder * Granulocyte count at least 1,000/mm\^3 * Platelet count at least 75,000/mm\^3 Hepatic * Bilirubin no greater than 2 times upper limit of normal (ULN) * AST and/or ALT no greater than 2 times ULN * Alkaline phosphatase no greater than 2 times ULN Renal * Creatinine no greater than 3 times ULN Cardiovascular * No prior spontaneous deep vein thrombosis within the past 5 years * Catheter-associated thrombus allowe…