Association of Flat Colorectal Adenomas with Advanced Synchronous Disease and Multiplicity

Flat adenomas were not more likely to have advanced histology themselves, but rather to predict the presence of synchronous advanced adenomas.

Recent study findings indicate that flat conventional adenomas in the colorectum are not more likely to harbor high-grade dysplasia or invasive cancer compared with polypoid adenomas. The increased risk for advanced histology seems confined to depressed lesions. Also, the association of flat adenomas with synchronous disease is not well understood.

To further investigate the risks for advanced histology and synchronous disease associated with flat adenomas, researchers conducted a retrospective analysis of data from three prospectively performed clinical trials. Of 1911 adenomas removed from 1340 patients, 15.3% were flat, and 84.7% were polypoid. Advanced histology was found in similar percentages of flat and polypoid adenomas (1.4% and 3.1%, respectively). Having at least one flat adenoma significantly predicted the presence of a large synchronous adenoma (odds ratio, 2.8), a synchronous advanced adenoma (OR, 2.7), and ≥3 adenomas (OR, 2.4).

Comment

These findings indicate that flat adenomas are not themselves more likely to harbor advanced neoplasia but rather that they predict the presence of synchronous advanced adenomas and multiple (≥3) synchronous adenomas. This suggests that patients with flat lesions warrant effective clearing for synchronous disease at both their baseline and follow-up examinations and that flat adenomas should be evaluated in future studies for possible use in determining postpolypectomy surveillance recommendations.

Reviewing Author

Douglas K. Rex, MD

Disclosures

Consultant/Advisory BoardOlympus Corporation America; Boston Scientific

Speaker’s BureauOlympus

Grant/Research SupportMedtronic; Boston Scientific; Colonary Solutions; Paion Medical; Medivators; Braintree Laboratories

Editorial BoardsWorld Journal of Gastroenterology; The Journal of Clinical Gastroenterology; Techniques in Gastrointestinal Endoscopy; Gastroenterology & Hepatology; Expert Review of Gastroenterology & Hepatology; Medscape Gastroenterology; World Journal of Gastrointestinal Pharmacology and Therapeutics; Annals of Gastroenterology & Hepatology; World Journal of Gastrointestinal Oncology; Comparative Effectiveness Research; Journal of Anesthesia & Clinical Research; Gastroenterology; World Journal of Gastrointestinal Pathophysiology; Gastroenterology Research and Practice; GI & Hepatology News; Gastroenterology Report; Clinical Epidemiology Reviews; JSM Gastroenterology and Hepatology; GI Journal Watch; Austin Journal of Gastroenterology; World Journal of Gastrointestinal Pharmacology & Therapeutics

Leadership Positions in Professional SocietiesAmerican Society for Gastrointestinal Endoscopy (Treasurer); US Multi-Society Task Force (AGA, ACG, ASGE) (Chair)