Rectal Abberant Crypt Foci And Other Intermediate Biomarkers For Sporadic Colorectal Neoplasia: Cross-Sectional Prevelance And Modulation By Celecoxib

OBJECTIVES:

Primary

• Compare the effects of celecoxib vs placebo on the number of rectal aberrant crypt foci in patients with premalignant rectal polyps or prior sporadic colorectal neoplasia.

Secondary

• Compare the effects of these drugs on proliferation index, apoptotic index, and gene expression patterns in ascending and descending colon tissue from these patients before and after treatment.
• Assess gene expression patterns in normal mucosa from the ascending vs descending colon in patients referred for screening, surveillance, or diagnostic colonoscopy.