March 4, 2013

Colorectal Cancer Awareness Month 2013 – Focus on Polyps

CDS News Update – 4th March 2013

Colorectal Cancer Awareness Month 2013 – Polyps

polyp-like acrophora

What are polyps?
A polyp is an abnormal growth or projection from the inner lining (mucosa) of the bowel wall. This outgrowth is typically warty or mushroom-like in shape.

colon polyp 2
Figure 1: A stalked colon polyp

What types of polyps are there?
Colon polyps vary in shape and size, as well as the types, numbers and locations.
Most colonic polyps are less than a centimetre in size. In terms of physical appearances, most colon polyps are mushroom-like, having a stalk. Others are flat (flat polyp) or carpet like (sessile polyp).
The growth and cancer potential of a colon polyp is best appreciated under a microscope (histology) after its removal. After the histological analysis, polyps can generally be classified as being
1. Adenomatous,
2. Hyperplastic,
3. Inflammatory,
4. Hamartomatous.

colon polyp
Figure 2: A sessile colon polyp

What is the cancer potential of colon polyps?
Adenomatous colon polyps have the potential of turning into colon cancer, given enough time. Therefore, patients with adenomatous colon polyps are at increased risk of developing colorectal cancer. Having the colon polyp removed at an early stage prevents the development of cancer in the polyp.

colon polyp to cancer
Figure 3: Polyp to colon cancer sequence

How long does it take for a colon polyp to turn into colon cancer?
Larger polyps have a greater risk of turning into colon cancer. It has been estimated that it takes about 5 to 10 years for cancerous change to occur.

How do I know if I have a polyp?
Unfortunately, most colon polyps are silent, especially when diminutive. Larger polyps can occasionally cause bleeding and rarely cause changes in bowel habits. As most colon polyps are silent and without symptoms, they are mostly detected on colonoscopy.

Who is at risk at developing colon polyps?
If you have blood in the stools or changes in bowel habits, investigations are recommended especially if you are more than 40 years of age or have a family history of cancer.
In addition, those with a previous cancer or polyp removed are at risk and should have routine surveillance colonoscopy.
Patients with known genetic syndromes such as Familial Adenomatous Polyposis (FAP) or Hereditary Non-Polyposis Colorectal Cancer (HNPCC) have a lifelong increased risk of developing multiple polyps and should undergo a regular screening programme.

How is a colon polyp removed?
Up to 90% of colon polyps can be safely removed via a colonoscopy. Small polyps are removed using biopsy forceps. Larger polyps are removed with a wire snare and electrocautery.
Please visit for further information on colonoscopy.

Figure 4: Using a snare to remove the polyp

Figure 5: The snare is applied to the stalk of the polyp and electrocautery is activated

Figure 6: The polyp is successfully removed

What happens after the polyp is removed?
Removed colon polyps are routinely sent to the laboratory for analysis under the microscope to determine its subtype. The cancerous potential can then be determined after this analysis, and recommendations can be made for follow-up.

How often will I need to have colonoscopy?
If there were adenomatous colon polyps removed during the colonoscopy, the regular recommendation is to have a repeat colonoscopy the year after.
However, if there were no colon polyps detected, the next colonoscopy can be scheduled 5 to 10 year after, depending on your risk profile.

About us:
The Clinic for Digestive Surgery offers screening of colon cancer and rectal cancer through colonoscopy packages. Gastroscopy for the screening of stomach cancer is also available as an option to the colonoscopy package. These packages are Medisave-claimable, and full coverage if often possible through comprehensive MediShield plans. While the Clinic is located at Mount Elizabeth Novena Hospital, where the colonoscopy can be performed, we will be most happy to perform the endoscopy at any private hospital in Singapore. At your convenience, we can schedule the colonoscopy to be performed at Mount Elizabeth Novena Hospital, Mount Alvernia Hospital, Parkway East Hospital, Gleneagles Hospital or Mount Elizabeth Orchard Hospital.

Dr Foo Chek Siang is a senior consultant endoscopist, having vast experience in both diagnostic and therapeutic gastroscopy and colonoscopy. He has also previously served as the Surgical Director in the Endoscopy Centre of Changi General Hospital, overseeing the training and accreditation of Endoscopists. He has also served as a member of the endoscopy accreditation committee, presiding over the experiences of prospective endoscopists and ensuring their credibility before approving their practices.

For questions about colon cancer, and on our Endoscopy packages, contact Clinic for Digestive Surgery at +65 6570 2702 to speak to SSN Karen, our Clinic Nurse. Alternatively, you could drop us an email at, or fill up the enquiry form at and we will attend to you at the soonest possible time.

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