Colorectal cancer screening

08.09.15

Dr. med. Michael Bardutzky

Krebsprävention durch Lebensstil?

In the industrialized countries, colorectal cancer is the second most common cancer after breast and prostate cancer. In Germany alone, more than 60000 people are diagnosed with this type of cancer and almost half of them die because of it. Colorectal cancer is a more aggressive and metastatic type of cancer as opposed to prostate cancer, for example. A rectum carcinoma refers to cancer affecting the rectum whereas a colon carcinoma refers to all other sections of the colon. Colorectal cancer (also known as colon cancer, rectal cancer or bowel cancer) is the development of cancer in the colon or rectum.

Apart from various (avoidable) aspects such as overweight and lack of exercise, the main risk factors for the development of colorectal cancer include wrong diet, smoking and genetic factors, for example if parents or siblings have developed this type of cancer at an early age.

Compared to the controversial screening techniques for breast cancer (mammography) or prostate cancer (PSA test), the colonoscopy fortunately offers a reliable preventative measure to detect problems at an early stage. Colon cancer almost never comes out of nowhere. Usually this disease develops out of a benign mucosal proliferation, a so-called polyp, that gradually becomes malignant after years of growth.

Colonoscopy is the only screening technique that allows the detection of such polyps. Any polyps found or suspected can be removed during the same procedure. After all, polyps as potential cancer precursors are detected by every fifth screening carried out for precautionary reasons. The rate of complications is marginal compared to the success rate of colon screening, which means that the benefits of a colonoscopy far outweigh the risks of side effects.

Of course, a colonoscopy is also associated with a certain effort. This type of screening is offered by gastrointestinal specialists (gastroenterologists). Appropriate specialists can be found in any major city in Germany. The preparation for the colonoscopy, i.e. bowel cleansing on the eve of the examination day, is what most people find unpleasant. The examination itself is usually performed under light anaesthesia and is therefore completely painless. However, the anaesthesia requires to keep free of other commitments on the examination day and not to drive a car. But it is worth the effort!

If the colonoscopy is considered negative, the next screening is recommended to be performed after ten years - the best evidence of its benefit in terms of cancer prevention. Time between tests may be shorter if polyps need to be removed. The screening interval may then be 5 years or earlier dependent on the histological findings. It may also be shorter in case of a genetic disposition. 

In general, routine screening colonoscopies should be carried out starting at age 50 at the latest or much earlier if people have a family history of cancer. They should get screened at least ten years earlier based on the age of the relative at onset of the disease.

In contrast to a routine screening colonoscopy, the alternative test for hidden (occult) blood in the stool can never safely exclude colorectal cancer or its precursors, even when using advanced test methods.

Lately, virtual colonoscopy via magnetic resonance imaging (MR colonography) has emerged as a non-invasive method for colon imaging. However, this method offered by radiologists may not detect smaller polyps. More intense bowel cleansing measures and an additional ‘genuine’ colonoscopy would be required in case of a positive result, which means twice the effort.

Based on current scientific data, including consideration of all risk and success factors, the colonoscopy remains the gold standard of colorectal cancer screening methods. We will gladly provide further information on this very important topic during your next health check-up at Praeveneo.

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