• INCLUSION CRITERIA:

Resident of Linxian, Henan Province, People's Republic of China.

40-69 years of age at the time of EGD screening.

Visible esophageal lesions with mild or moderate squamous dysplasia found at the t(-6) EGD screening exam.

Confirmation of a visible index lesion at the t(0)EGD baseline exam.

Willing to abstain from chronic NSAID use (defined as greater than 3 times per week for more than 2 weeks), with the exception of low-dose aspirin (less than or equal to 100 mg per day), for the duration of the study.

If a subject is female and of child-bearing potential (premenopausal or less than 2 years postmenopausal and not surgically sterile), she must be willing to use adequate contraception (abstinence, IUD, birth control pills, or spermicidal gel with diaphragm or condom) for the duration of the study.

Appropriate laboratory values within 2 weeks of the baseline evaluation for :

hemoglobin greater than 11.0 g/dl;

WBC greater than 3000/mm(3);

platelet count greater than 100,000;

creatinine less than or equal to 1.5 times the upper limit of normal;

AST less than or equal to 1.5 times the upper limit of normal;

Alkaline phosphatase less than or equal to 1.5 the upper limit of normal;

Pregnancy test negative serum or urine (women of childbearing potential only).

Only those patients with mild or moderate dysplasia based on the t(-6) histology and endoscopically visible lesions at the t(0) evaluation will be eligible for participation and inclusion in the study.

To be eligible at t(0), subjects must have a confirmed, endoscopically visible lesion.

EXCLUSION CRITERIA:

Diagnosed cancer at any site, except non-melanoma skin cancer.

Current symptoms suggestive of an upper gastrointestinal tract malignancy, including dysphagia, odynophagia, hematemesis, or weight loss of greater than 10% body weight within the past 6 months.

Contraindications to the EGD exams, including hypersensitivity to lidocaine or iodine, uncontrolled congestive heart failure, unstable angina, bleeding disorder or severe pulmonary disease.

Contraindications to use of the intervention agents, including hypersensitivity to selenomethionine, COX-2 inhibitors, NSAIDs, salicylates, or sulfonamides.

Treated for peptic ulcer disease within the past month prior to the baseline evaluation.

Acute or chronic kidney disease, liver disease, or asthma.

Pregnant or nursing an infant.

Other serious health condition that might preclude study completion (at the discretion of the investigators).

Currently using fluconazole or lithium.