Chemoprevention of colonic polyps with balsalazide: an exploratory, double-blind, placebo-controlled study.
BACKGROUND
A number of agents, including aspirin, nonsteroidal antiinflammatory drugs, cyclooxygenase-2 inhibitors, folic acid, calcium, and vitamins, have been evaluated for their potential in chemoprevention of sporadic colorectal adenomas or cancer. Preclinical data suggest that 5-aminosalicylates also may have a chemopreventive effect.


OBJECTIVE
To investigate chemoprevention of colonic polyps with balsalazide, a 5-aminosalicylate prodrug.


METHODS
In this randomized, double-blind, placebo-controlled study, adults diagnosed with small polyps in the rectosigmoid colon were treated with either balsalazide 3 g/d or placebo for 6 months. Follow-up lower endoscopy was performed, and all polyps were measured and analyzed histologically. The primary endpoint was reduction in mean size of the largest polyp per subject.


RESULTS
Among 241 participants screened, 86 were randomized to treatment, with 75 subjects evaluable. Balsalazide 3 g/d (n = 38) did not significantly reduce the mean size of the largest colonic polyp or the number of polyps compared with placebo (n = 37). Although not significant, post-hoc analysis revealed that total adenoma burden per subject, calculated as the sum of the volumes of all adenomas in mm3, increased by 55% in the balsalazide group compared with 95% in the placebo group.


CONCLUSIONS
Although balsalazide did not have significant chemopreventive effects on established colonic polyps, these results can aid in designing future prospective studies.
Terdiman
Jonathan P
JP
Division of Gastroenterology, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. Jonathan.Terdiman@ucsf.edu
Johnson
Lorin K
LK
Kim
Young S
YS
Sleisenger
Marvin H
MH
Gum
James R
JR
Hayes
Ann
A
Weinberg
Vivian K
VK
McQuaid
Kenneth R
KR
D000236:Adenoma / Q000473:pathology / Q000517:prevention & control; D000368:Aged; D017209:Apoptosis / Q000187:drug effects; D012809:Colon, Sigmoid / Q000473:pathology; D003110:Colonic Neoplasms / Q000473:pathology / Q000517:prevention & control; D003111:Colonic Polyps / Q000473:pathology / Q000517:prevention & control*; D004311:Double-Blind Method; D005765:Gastrointestinal Agents / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D019804:Mesalamine / Q000494:pharmacology / Q000627:therapeutic use*; D008875:Middle Aged; D010659:Phenylhydrazines / Q000494:pharmacology / Q000627:therapeutic use*; D011446:Prospective Studies
D005765:Gastrointestinal Agents; D010659:Phenylhydrazines; D019804:Mesalamine; C038637:balsalazide