Colonoscopy reduces the risk of cancer

Cancer Research: Colonoscopy significantly reduces cancer risk

01/05/2011

Scientists at the German Cancer Research Center (DKFZ) have used a comprehensive study to investigate how colonoscopy has an effect on the risk of cancer in the various sections of the intestine. It has been scientifically proven for a long time that endoscopic colonoscopy with simultaneous removal of the polyps considerably reduces the risk of cancer in the left part of the intestine. For the remaining sections of the gut, researchers from the DKFZ research group on the subject of Hermann Brenner are now providing scientifically sound results for the first time. Brenner and colleagues have found that colonoscopy not only significantly reduces the cancer risk in the left part of the colon, as expected (by 84 percent), but also reduces the risk of cancer by more than 50 percent in the right part of the colon.

Overall, their investigations have revealed a reduction of the colorectal cancer risk by 77 percent, the researchers report in the latest issue of the journal „Annals of Internal Medicine“. Colonoscopy, for example, generally provides very good protection against colon cancer, although no one hundred percent certainty is possible, stressed Hermann Brenner. According to the DKFZ scientists, the fact that a reduction in the cancer risk of 56 percent is also achieved in the right section of the large intestine is particularly pleasing.

Reduce cancer risk by 77 percent
In the course of their study, the researchers of the DKFZ interviewed 1,688 colon cancer patients after past colonoscopy and their medical findings in the ten years before the diagnosis. As a control, the same information was also requested from 1,932 healthy persons. On the basis of the data collected, the epidemiologists of the DKFZ calculated that the effect of a previous colonoscopy, in which possibly discovered cancer precursors were removed, on the risk of cancer in the entire intestinal area. In doing so, they noted the aforementioned reduction in the overall risk of malignant colon cancer by 77 percent. However, the researchers also separately calculated the risk reduction for the various anatomical sections of the gut, with the result presented above.

Colonoscopy offers good options for protection against cancer
According to the DKFZ working group, their studies underscore the considerable potential of colonoscopy for the prevention of colorectal cancer. Brenner recommends: „However, physicians should educate their patients that endoscopic examination of the gut provides very good protection against colon cancer - but not 100% certainty“ suggest. The deviations compared to other international studies, which only a clear reduction of cancer risk in the left „descending“ Could determine the large intestine section, explained the researchers of the DKFZ, „In Germany, great importance is attached to the quality assurance of the examinations and therefore the more difficult to detect cancer precursors are recognized“. The different levels of risk reduction in the different sections of the intestine lead Brenner and colleagues back to the fact that cancer precursors in the right part of the intestine can be more easily overlooked, because they are more often flat and inconspicuous. Also, the right part of the colon can not be fully seen in all cases, while left colon is good to survey and the colon cancer precursors usually occur here as prominent polyps. In addition, the researchers of the DKFZ suspect differences in the biological behavior of the tumor cells in the various intestinal sections. (Fp)

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Colon cancer avoided by colonoscopy

Image: Dieter Schütz