Aspirin and folic acid for the prevention of recurrent colorectal adenomas.
OBJECTIVE
Although observational studies have found regular aspirin use to be associated with a reduced risk of colorectal neoplasia, results from randomized trials using aspirin have been inconsistent. Dietary folate intake also has been found to be associated with a reduced risk of colorectal neoplasms in observational studies.


METHODS
A multicenter, randomized, double-blind trial of aspirin (300 mg/day) and folate supplements (0.5 mg/day) to prevent colorectal adenoma recurrence was performed using a 2 x 2 factorial design. All patients had an adenoma (>/=0.5 cm) removed in the 6 months before recruitment and were followed-up at 4-month intervals with a second colonoscopy after approximately 3 years. The primary outcome measure was a colorectal adenoma diagnosed after baseline.


RESULTS
A total of 945 patients were recruited into the study, of whom 853 (90.3%) underwent a second colonoscopy. In total, 99 (22.8%) of 434 patients receiving aspirin had a recurrent adenoma compared with 121 (28.9%) of 419 patients receiving placebo (relative risk, 0.79; 95% confidence interval [CI], 0.63-0.99). A total of 104 patients developed an advanced colorectal adenoma; 41 (9.4%) of these were in the aspirin group and 63 (15.0%) were in the placebo group (relative risk, 0.63; 95% CI, 0.43-0.91). Folate supplementation was found to have no effect on adenoma recurrence (relative risk, 1.07; 95% CI, 0.85-1.34).


CONCLUSIONS
Aspirin (300 mg/day) but not folate (0.5 mg/day) use was found to reduce the risk of colorectal adenoma recurrence, with evidence that aspirin could have a significant role in preventing the development of advanced lesions.
Logan
Richard F A
RF
Division of Epidemiology and Public Health, University of Nottingham, University Hospital, Nottingham, United Kingdom. Richard.Logan@nottingham.ac.uk
Grainge
Matthew J
MJ
Shepherd
Vic C
VC
Armitage
Nicholas C
NC
Muir
Kenneth R
KR
D000236:Adenoma / Q000628:therapy*; D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000628:therapy*; D004311:Double-Blind Method; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D006397:Hematinics / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D006397:Hematinics; D005492:Folic Acid; D001241:Aspirin