1. Louisiana Tumor Registry and Epidemiology Program; School of Public Health, Louisiana State University Health Sciences Center; New Orleans Louisiana
2. Department of Epidemiology; College of Public Health, University of Iowa; Iowa City Iowa
3. Department of Pathology; School of Medicine, Louisiana State University Health Sciences Center; New Orleans Louisiana
4. Division of Gastroenterology; School of Medicine, Tulane University; New Orleans Louisiana
5. Surveillance Research Program, Division of Cancer Control and Population Sciences; National Cancer Institute; Rockville Maryland
6. Cancer Diagnosis Program, Division of Cancer Treatment and Diagnosis; National Cancer Institute; Rockville Maryland