Colon Cancer & Polyps
Why early detection matters
Colorectal cancer (CRC) develops in the colon or rectum. In most cases, it starts as a small growth called a polyp. Not all polyps become cancer, but removing them eliminates the risk.
Colorectal cancer in Canada
- 1It's the 3rd most commonly diagnosed cancer in Canada
- 2About 1 in 14 Canadian men and 1 in 18 Canadian women will develop CRC in their lifetime
- 3When found early (Stage I), the 5-year survival rate is over 90%
- 4When found late (Stage IV), the 5-year survival rate drops to about 14%
- 5Regular screening can prevent up to 60% of CRC deaths
What are polyps?
Polyps are small growths on the inner lining of the colon. They're very common — about 25-40% of people over 50 have them.
Hyperplastic polyps
Low riskUsually small and found in the lower colon. These rarely become cancerous.
Adenomatous polyps (adenomas)
Moderate riskThe most common type that can develop into cancer over time (usually 10-15 years). This is why they're removed during colonoscopy.
Sessile serrated polyps
Moderate to High riskFlat polyps that can be harder to spot. They have a higher potential to become cancerous and are an important reason for thorough colonoscopy.
The polyp-to-cancer journey
Most colon cancers develop slowly from polyps over 10 to 15 years. This long timeline is exactly why screening works so well — there's a large window to find and remove polyps before they ever become dangerous. A colonoscopy interrupts this process by removing polyps during the exam.