bowel cancer screening |What test for screening for bowel cancer?

What test for screening for bowel cancer?






The Conseil supérieur de la Santé (CSS) has recently decided in favor of the use of immunological tests in colorectal cancer screening programs. What to say?
Source: communiqué of the High Council of the Health of the 15/07/2013

Screening for bowel cancer is helpful ...
In the Wallonia-Brussels Federation, a screening program for colorectal cancer (large bowel cancer) has been in place since 2009. Those of you between the ages of 50 and 74 have certainly already received an invitation to do so. This is a useful test as colorectal cancer is the second leading cause of cancer death in our country. It is possible to cure it when diagnosed at a beginning stage, but it becomes much more difficult if it is discovered at an advanced stage (and unfortunately it is still often the case).

Screening is based on the detection of "occult" blood in the stool. This blood is said to be occult, that is to say, "hidden", because it is about micro-traces not visible to the naked eye, coming from polyps or cancers that bleed in the intestine. Most cancers of the large intestine result from the transformation of benign polyps into malignant tumors. Detecting their presence through occult traces of blood in the stool thus allows polyps to be removed before they are transformed, or early cancers before they spread. This implies that, if the test is positive, the person passes a colonoscopy (examination of the large intestine using a flexible tube introduced by the anus). This colonoscopy then makes it possible to locate the possible lesions and even to remove the polyp or polyps. Often the story ends there, the patient is healed.

... but the test used poses question
However, there are disagreements on the test to be used to detect these traces of blood. The one currently used in the Wallonia-Brussels Federation (guaiac test) is cheap, but impractical. Indeed, it is necessary to make three stool samples for three days in a row. This can be done at home in peace, but many people are reluctant to perform this little intimate exercise.

There is another "immunochemical" test that is more expensive, but all at once, which allows for better participation of the population. This is an important condition of effectiveness for a screening program! But it is not the only one. Indeed, it is also necessary that the tests are sufficiently sensitive (able to detect minute anomalies) and specific (do not give false alarms). In this respect, the two tests are neck and neck: the immunological test is more sensitive and the guaiac test is more specific. All these arguments were analyzed by the CSS, which concluded that the cost-effectiveness ratio was in favor of the immunoassay.

Flanders will launch in September 2013 a screening program using the immunoassay. As for the Wallonia-Brussels Federation, which has been testing for several years, it is feeling: should we change the test? The Cancer Foundation believes yes.

Another important detail: in Flanders, the screening program will be aimed directly at all people between the ages of 50 and 74, while in the French-speaking part of the country, it is necessary to go through the general practitioner. The Foundation against Cancer will be attentive to the results obtained in the north and south of the country, to see if one of these two approaches gives better results and deserves to be applied from Ostend to Arlon ...