Colorectal cancer

In the UK, there are approximately 40,000 new cases of bowel cancer each year. It is the 3rd most common form of cancer in both men and women in the UK. Overall, about 1 in 20 people will get bowel cancer in their lifetime.

Screening can help detect bowel cancer at an early stage, when treatment is more likely to be curative. Screening may also detect polyps in the colon, some of which can turn cancerous over time. Currently in the UK there are 2 types of screening for bowel cancer offered:

  • Faecal occult blood test (FOB test) – this is a home screening kit which is used to detect tiny amounts of blood in the stool. If the test is positive, a colonoscopy test is then performed to look for polyps and/or bowel cancers. The reasoning for this test is that large polyps or early cancers may have resulted in some occult bleeding in the large bowel which results in blood becoming mixed in with the stool. A kit is currently sent out to all adults aged 60-75 in England every 2 years. It has recently been announced that the age in England will be lowered to 50. This change brings England in line with Scotland where bowel screening is automatically offered from the age of 50.
  • Bowel scope screening – this test is currently being rolled out to all men and women in England at the age of 55. Essentially it uses a thin flexible camera to look predominantly for polyps in the left side of the colon and rectum. This test is also called a flexible sigmoidoscopy. The rationale for this test is that it may remove a polyp which if left inside could continue to grow and become cancerous.

 

Colonoscopy

The so called ‘gold standard’ screening procedure for preventing colon cancer is a Colonoscopy.

In this test the bowels have to be cleared of all the faeces with strong laxatives prior to the test. A flexible camera (colonoscope) is then used to look around the whole of the large intestine (colon and rectum). The rationale for this examination is to remove any polyps found in the colon and rectum. This is not to say that all of these polyps would become cancerous, but some of them would have the potential to continue to grow and become cancerous over a number of years. Currently in the UK, colonoscopy is only offered as a screening test to individuals with a strong family history of colorectal cancer.

In the USA, the American Cancer Society Guidelines recommend that people at average risk of colorectal cancer start regular screening at the age of 45. People who are deemed to be at average risk are those people with no family history of colorectal cancer, or personal history of certain types of polyps or inflammatory bowel disease.

As a result of these guidelines, many asymptomatic individuals in the USA will undergo a colonoscopy every 10 years beginning at the age of 50. If you would like to come and discuss the screening for bowel cancer in more detail, particularly with regards the use of colonoscopy, I would be very willing to discuss this with you.