Numbers of Tissue Samples and Patients, Classifications, and Sources.

P(0-2), P(2-4), and P(4-): progressor samples obtained 0�C2 years, 2�C4 years, or more than 4 years before the progression date, respectively; NP: non-progressor samples; MAYO: Mayo Clinic Foundation; UMD: University of Maryland and VA Baltimore Medical Centers; S.D.: standard deviation; BE: non-dysplastic Barrett's esophagus; LGD: low-grade dysplasia, HGD: high-grade dysplasia; EAC: esophageal adenocarcinoma; Pathology: for non-progressor patients, the most neoplastically advanced pathology; for progressor patients, pathology at the study endpoint; *: number of patients developing EAC subsequent to a diagnosis of HGD.