Celecoxib or Observation After Radiation Therapy and Chemotherapy in Treating Patients With Stage II or Stage III Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: Histologically or cytologically confirmed non-small cell lung cancer meeting ≥ 1 of the following criteria: Stage IIIB disease Stage II or IIIA disease, meeting the following criteria: Considered nonresectable Pleural effusion present Measurable disease Must have received a prior regimen of radiotherapy and chemotherapy comprising docetaxel and carboplatin Tumor volume must be able to be encompassed in the radiation field PATIENT CHARACTERISTICS: ECOG performance status 0-2 Life expectancy > 12 weeks Cardiac function compatible with radiotherapy Neutrophil count ≥ 2,000/mm³ Platelet count ≥ 100,000/mm³ Hemoglobin ≥ 10 g/dL Creatinine ≤ 1.5 times upper limit of normal (ULN) Bilirubin ≤ 1.25 times ULN AST and ALT ≤ 1.5 times ULN Alkaline phosphatase ≤ 2.5 times ULN Not pregnant or nursing No other malignancy in the past 10 years except basal cell skin cancer or carcinoma in situ of the cervix No active infection No inflammatory bowel disease No severe congestive heart failure No severe hepatic disease defined as albumin < 25 g/L or Child-Pugh score ≥ 10 No severe renal disease defined as creatinine clearance < 30 mL/min No known hypersensitivity to sulfonamides, the study or it's excipients, or polysorbate 80 No known hypersensitivity of NSAIDs, salicylic acid, or cyclo-oxygenase-2 inhibitors No familial, social, geographical, or psychological condition that would preclude study compliance PRIOR CONCURRENT THERAPY: See Disease Characteristics More than 30 days since participation in another clinical study More than 1 month since prior therapy for gastrointestinal ulcers No concurrent fluconazole, ketoconazole, lithium, or dextromethorphan No other concurrent anticancer treatment including chemotherapy, hormonal therapy, radiotherapy, immunotherapy, or biologic response modifier therapy No concurrent aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) Low-dose aspirin or NSAIDs for a duration of ≤ 1 week during the past 3 months allowed