Temozolomide, Thalidomide, and Celecoxib Following Radiation Therapy in Treating Patients With Newly Diagnosed Glioblastoma Multiforme

DISEASE CHARACTERISTICS: * Histologically confirmed supratentorial glioblastoma multiforme or gliosarcoma * Completed standard external beam radiotherapy within the past 5 weeks * Stable disease by MRI or CT scan PATIENT CHARACTERISTICS: Age * 18 and over Performance status * Karnofsky 60-100% Life expectancy * More than 4 months Hematopoietic * Absolute neutrophil count at least 1,500/mm3 * Platelet count at least 100,000/mm3 * No history of bleeding disorder Hepatic * Bilirubin less than 1.5 mg/dL * SGPT less than 2.5 times normal * Alkaline phosphatase less than 2.5 times normal Renal * BUN less than 1.5 times upper limit of normal (ULN) OR * Creatinine less than 1.5 times ULN Cardiovascular * No deep vein thrombosis within the past 3 weeks (must be clinically stable) Pulmonary * No pulmonary embolism within the past 3 weeks (must be clinically stable) Other * Must participate in System for Thalidomide Education and Prescribing Safety program * No peripheral neuropathy grade 2 or greater * No active infection * No concurrent illness that may obscure toxicity or dangerously alter drug metabolism * No other serious concurrent illness * No other malignancy within the past 3 years except nonmelanoma skin cancer or carcinoma in situ of the cervix * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use 2 forms of effective contraception for 1 month before, during, and for 1 month after study PRIOR CONCURRENT THERAPY: Biologic therapy * No prior thalidomide * No concurrent immunotherapy * No concurrent prophylactic filgrastim (G-CSF) Chemotherapy * No prior chemotherapy * No other concurrent chemotherapy Endocrine therapy * No concurrent hormonal therapy * Concurrent corticosteroids must be at stable or decreasing dose over the past 7 days Radiotherapy * See Disease Characteristics * No concurrent radiotherapy Surgery * No concurrent surgery Other * No other concurrent anticancer therapy * No other concurrent investigational agents