Celecoxib in Treating Patients With Early-Stage Head and Neck Cancer or Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: * One of the following histologically confirmed diagnoses: * Stage I non-small cell lung cancer (NSCLC) * No small cell component * Stage I-II squamous cell cancer of the head and neck * No WHO type II or III nasopharyngeal cancer * No sinonasal undifferentiated carcinoma * No evidence of disease * Must have undergone surgery or radiotherapy with curative intent within the past 4-24 weeks PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-1 Life expectancy * Not specified Hematopoietic * Platelet count at least 50,000/mm\^3 Hepatic * Bilirubin normal * AST/ALT no greater than 2 times upper limit of normal Renal * Creatinine no greater than 2.0 mg/dL Cardiovascular * No uncontrolled hypertension * No severe congestive heart failure Pulmonary * No history of asthma caused by cyclooxygenase-2 (COX-2) inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDs), salicylates, or sulfonamides Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for 3 months after study participation * No other prior malignancy (including skin cancer and in situ malignancies) * No diagnosis of peptic ulcer disease or gastritis/esophagitis within the past 60 days * No prior hypersensitivity reaction to COX-2 inhibitors, NSAIDs, salicylates, or sulfonamides * No other concurrent medical condition that would preclude study compliance PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * Not specified Endocrine therapy * No cumulative oral or IV corticosteroid use totalling more than 2 weeks within the past 3 months * No concurrent oral steroids for more than 2 consecutive weeks * Concurrent inhaled steroids allowed Radiotherapy * See Disease Characteristics * No prior definitive radiotherapy for stage I NSCLC Surgery * See Disease Characteristics * Prior pneumonectomy or lobectomy with mediastinal lymph node sampling or dissection for stage I NSCLC allowed * No prior segmentectomies or wedge resections for stage I NSCLC Other * More than 60 days since prior treatment for peptic ulcer disease or gastritis/esophagitis * No prior NSAID use within the past 30 days at a frequency of 3 or more times a week for more than 2 weeks * No concurrent NSAIDs (including low-dose aspirin) * No other concurrent COX-2 inhibitors * No concurrent fluconazole * No concurrent lithium