Serum salicylate levels and risk of recurrent colorectal adenomas

Background: Intake of aspirin is associated with reduction in risk of colorectal adenoma and carcinoma. Some plants contain salicylates, and individuals not taking aspirin may have measurable salicylate levels. However, the association between serum salicylate level and recurrence of adenoma in nonusers of aspirin has not been studied. Methods: We measured serum salicylate levels in participants in a randomized controlled trial with calcium supplementation for the prevention of colorectal adenomas. Generalized linear models were used to assess the association between serum levels and adenoma risk during the follow-up period of the trial. Results: We did not find an association with recurrence of adenomas or advanced adenomas with serum salicylate levels at year 1 among nonusers of aspirin. There was no effect modification of the chemopreventive effect of calcium supplementation in reducing risk of recurrent adenomas or advanced adenomas. Conclusions: Among nonusers of ASA, serum salicylate levels are not associated with risk of recurrence of adenomas. Impact: Serum salicylate levels can be detected in individuals not taking aspirin, but the levels may be too low to confer protection from risk of recurrent adenomas.