Why to do Screening colonoscopy?
Ontario has among the highest rates of colorectal cancer in the world. Colorectal cancer is the fourth most commonly diagnosed cancer in Ontario. It is also the second leading cause of cancer deaths in men after lung cancer and the third leading cause of cancer deaths in women after lung and breast cancers.
A person with colorectal cancer has a 90% chance of being cured if the cancer is caught early enough through screening. Colorectal cancer screening can be the difference between life and death. (CCO 2015)
It is estimated that one in 14 men will develop colorectal cancer during their lifetime, and one in 27 will die of it; one in 15 women will develop colorectal cancer during their lifetime, and one in 31 will die of it. (CCS 2009)
Ways to screen for Colon Cancer:
- Colonscopy is a best available way to screen for Colorectal Cancer.
- Sigmoidoscopy is partial colonoscopy. It only allows to see the last third of the colon. In this area most of Colon Cancer tends to develope.
- Fecal Occult blood test (FOBT) is a screening test that looks for microscopic blood in the stool. It is not specific as it will detect blood from many sources. Also, early cancers and polyps do not bleed therefore cannot be detected by this test.
- CT colonography – it is an X-Ray based imaging that allows to see colon lining against a contrast material. This test is reserved for cases when Colonoscopy cannot be completed. This test will not detect small polyps and may confuse bowel content with polyps. During this test polyps cannot be removed.
- Blood tests for Colon Cancer – these tests do not have suffcient evidence to recommend or not for use as a screening method for Colon Cancer and are not covered by OHIP.
- Capsule Endoscopy is not recommended screening method for Colon Cancer as this technology can still miss cancer and polyps. It cannot remove polyps. It is not covered by OHIP.
What are the colonoscopy and gastroscopy?
COLONOSCOPY is a direct way of looking at the lining of your large intestine for abnormalities. A flexible telescope is passed through the anus and around the colon. If polyps (precancerous lesions) or small cancers are found, they are usually removed during this procedure or very small tissue samples (biopsies) can be taken and sent for tests.
Click to See Educational Video on Colonoscopy
GASTROSCOPY is a direct way of looking at the esophagus, stomach, small bowel and this is done by passing a thin flexible telescope to the back of your throat and down into your esophagus.
What are the risks?
- Colonoscopy and gastroscopy are safe procedures and have very low risks. However, possible complications are:
- Perforation (a tear) in the colon wall after the colonoscopy – about 1 in 1,500 or following removal of a polyp – about 1 in 500. It may require surgery to repair or be managed with antibiotics and intravenous fluids.
- Bleeding following a colonoscopy – about 1 in 2,000 or following removal of a polyp – about 1 in 500.
- Allergic reactions to the intravenous medications (including rash, fever or breathing problems).
- A tender lump where the intravenous is placed in your arm may develop which may stay for up to several months but goes away. Apply warm packs to relieve the discomfort.
- Heart problems, or a stroke can occur in a patient with underlying medical problems, but are very rare.
- Severe damage to teeth, mouth, throat, vocal cords, oesophagus or stomach during a gastroscopy is very rare.
- Lung or gastrointestinal tract infections are very rare.
- No test in medicine is perfect: rarely polyps and cancers are missed in 2-6%.