Polyps and Colon Cancer

In Ontario, colon cancer is the second most common cause of cancer-related death. The good news – with proper screening, this disease can be prevented.

Within in the colon, normal cells can develop abnormal changes in them and become “adenomas.” Adenomas can develop as small growths (polyps) in the colon. If these are detected early and removed, colon cancer does not develop. Once an adenoma develops, it may take up to 10 years for it to grow and change into a cancer. There is enough time for polyps to be detected by colonoscopy and removed. Unfortunately, if colon cancer is not detected in the early stages, it spreads beyond the colon and adequate treatment is not effective to provide a cure.

Removal of Polyps: Most polyps can be removed safely by colonoscopy before they become cancers. This exam can detect up to 97% of all polyps and cancers.

What are colon polyps?

Polyps are an overgrowth of tissue lining the inner wall of the colon. These may be mushroom shaped (pendunculated) or flat (sessile). Small polyps are usually harmless but may contain abnormal cells that have the potential to grow and become cancerous. The larger the polyp the greater the risk of malignancy (cancer).


How are polyps removed?

After the colon is cleaned out, a flexible, lighted tube (endoscope) with a camera allows the physician to view the lining of the colon on a video screen. Polyps may be removed by a wire snare placed tightly around the base. Cautery is used as the polyp is cut off to prevent bleeding. All tissue retrieved is sent to the pathology lab for examination and to determine proper follow-up.