• Polymorphisms in detoxifying enzyme systems such as glutathione S-transferases (e.g., mu, theta, pi)
  
• Polymorphisms in other xenobiotic metabolism pathways (e.g., CYP1A1, CYP2E1, CYP3A4/5, NQO1, mEH, NAT-2)
  
• Polymorphisms in inflammatory gene pathways (e.g., MPO, MnSOD, IGF, IGFBF3, Il1-beta)
  
• Polymorphisms in DNA repair genes or the p53 pathways (e.g., ERCC2, XRCC1, p53, p73, CCND1, p21)
  

OBJECTIVES:

• Assess the role of several genetically determined factors that, in combination with CagA status, cigarette smoking, alcohol, and diet to varying degrees, result in an increased risk for Barrett's esophagus.

OUTLINE: This is a controlled study.

Patients complete questionnaires about demographics, medical history, smoking and alcohol history, current medications, frequency and chronicity of gastroesophageal reflux symptoms, and diet history.

Blood and tissue are collected and analyzed by DNA-based assays and enzyme-linked immunosorbent assay for CagA status and polymorphisms in detoxifying enzyme systems, other xenobiotic metabolism pathways (e.g., CYP1A1, CYP2E1, CYP3A4, CYP3A5, NQO, NAT-2), inflammatory gene pathways (e.g., IGF, IGFBF3), and in DNA repair genes or p53 pathways (e.g., XRCC1, p53 gene).

PROJECTED ACCRUAL: A total of 350 patients will be accrued for this study.