How Often Should Colonoscopy Follow-Up Be Performed After Polypectomy?

• What Is Colonoscopy? Why and How Is It Performed?

Adenomas (polyps), play an important role, particularly in the development of colorectal cancer. Therefore, after age 50, every 10 years, colonoscopy (examination of the large bowel by inserting a thin, flexible tube with a camera through the anus) should be performed to detect any such growths and remove them using the polypectomy method .

This relatively simple procedure substantially reduces the risk of large bowel cancer (colon and rectum = colorectal cancer) . However, colorectal cancer can still develop later after polypectomy. Patients who undergo polypectomy should therefore also receive colonoscopy follow-up at certain intervals. These intervals naturally depend on the grade of the removed adenoma and its risk of becoming cancerous later. Yet there have not been enough comprehensive studies on colorectal cancer incidence and mortality after polypectomy. A comprehensive study on this subject was recently published in one of the most prestigious medical journals, the British medical journal(NEJM).

In this study, approximately 40.000 people who had colorectal adenomas removed by polypectomy were followed for about 8 years to evaluate colorectal cancer incidence and mortality.

Patients were classified according to whether the removed adenomas were low or high risk, and the appropriate intervals for colonoscopy follow-up were examined accordingly.

When the data were examined, colorectal cancer incidence and mortality in patients whose removed adenomas were low risk were similar to rates in the general population. In other words, colonoscopy follow-up after polypectomy was not found to be essential for these individuals. In patients whose removed adenomas were high risk, these rates after polypectomy were higher than expected. Thus, patients in the high-risk group must receive colonoscopy follow-up at specified intervals after polypectomy.

In conclusion, follow-up strategy after removal of colorectal adenomas is an important issue. It should be updated as needed in light of new studies and evidence. This study suggests that follow-up is not essential after removal of low-risk adenomas, whereas for high-risk adenomas the current interval of every 3 years could be shortened somewhat. However, these findings need support from further studies.