Using orally administered zinc to patients already diagnosed with the pre-cancerous condition, Barrett's Esophagus, this study is asking two questions:

1. can this zinc administration cause molecular-level changes in the Barrett's tissue?
2. are the changes measured indicative of chemopreventive action by zinc regarding cancer progression?

14 days prior to already-scheduled upper endoscopy (EGD) procedures for routine surveillance of Barrett's tissue, patients who have given written, informed consent are randomized (sealed envelope method) and placed on an oral dose of zinc gluconate (26.6 mg zinc BID) or a placebo (molar equivalent of sodium gluconate BID) for 14 days. At the time of endoscopy, 4 biopsies are taken (and pooled) from the Barrett's tissue and 4 from proximal normal esophageal tissue. Biopsies are flash frozen for later analyses by atomic absorption spectroscopy, PAGE and Western immunoblot or RNA microarray.

Inclusion Criteria:ages 18-80; prior diagnosis of Barrett's esophagus -

Exclusion Criteria:unable to provide written, informed consent; prior history of Barrett's dysplasia or esophageal adenocarcinoma; drug exclusions: hormone replacement therapy, cholestyramine, amiloride diuretics, oral quinolone antibiotics, glucocorticoids, corticosteroids, anticoagulants (other than aspirin)

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