DOWNERS GROVE, Ill., April 14 (UPI) — Flat adenomas, precancerous polyps in the colon that do not have a typical appearance, can indicate the presence of larger adenomas that have a greater chance of being cancerous, according to a new study.
Researchers at Loyola University Medical Center said doctors should examine patients more closely and more often when flat adenomas have been found because of the link to more frequent occurrence of large, advanced adenomas appearing at the same time.
Removal of adenomas significantly decreases the risk for colon cancer, though polyp type differs from patient to patient. Indicators of higher risk — such as the presence of flat adenomas — need to be screened for regularly in order to catch cancer earlier.
For the study, published in the journal Gastrointestinal Endoscopy, researchers analyzed data from three clinical trials where patients had colonoscopies for either screening or surveillance purposes.
In the trials, 2,931 polyps were removed from 1,340 patients. Of 1,911 ademonas removed from patients, accounting for 65.2 percent of polyps doctors removed, 15.3 percent were flat, while 84.7 percent were polypoid.
The analysis showed patients with at least one flat adenoma were more likely to have a large adenoma or three or more adenomas overall, an indication that could potentially allow doctors to head off more cancer before it starts.
The link between flat adenomas and higher-risk polyps will need to be explored in future studies, including whether patients could benefit from shorter surveillance intervals after a flat adenoma has been found, researchers wrote.