colon cancer screening | Screening for colorectal cancer (colon and rectum)

Screening for colorectal cancer (colon and rectum)



Description
Targeted persons
Screening method
Benefits and limitations of RSOSi screening
Some numbers
Description
Colorectal cancer, commonly known as colon cancer, usually develops very slowly. A person can have this cancer for years before having symptoms.

Screening is designed to detect and treat colorectal cancer before signs and symptoms appear. Generally, at the time of screening, the cancer is at an early stage and the possibilities of healing are better.

Targeted persons
Screening is especially for people aged 50 to 74, since the risk of developing colorectal cancer increases from 50 years.

Screening could start before the age of 50 for people who are at higher risk of developing colorectal cancer.

Screening method
Medium risk people
In Quebec, screening for colorectal cancer in people at medium risk, without symptoms and without other risk factors, is recommended every 2 years. Screening is done using the immunochemical fecal occult blood test (fOBT). This test does not tell you whether or not you have colorectal cancer, but it can detect the presence of blood in the stool, which can be a sign of cancer.

When the result of the RSOSi test indicates the presence of blood in the stool, the doctor recommends another examination to establish the diagnosis, the long colonoscopy. This exam visualizes the interior of the large intestine to check for cancer.

People at higher risk
For those at higher risk, the physician determines the screening method based on the specific situation of each person.

If you are in this situation, discuss with your doctor the recommendations that apply to you.

Benefits and limitations of RSOSi screening
You may decide to be screened for colorectal cancer or not. It's a personal choice, which belongs to you. If you have any questions or concerns about this, discuss it with your doctor.

Advantages
Screening reduces the risk of dying from colorectal cancer. Out of 1,000 people who are screened, 5 deaths are avoided.

Colorectal cancer usually develops very slowly. Taking the RSOSi test every 2 years increases the chances that the cancer will be discovered and treated at an early stage. The necessary treatments could also be less aggressive.

In addition, when a long colonoscopy is necessary, the doctor can see if there are polyps on the inner walls of the large intestine. Polyps are small masses of flesh that can turn into colorectal cancer. The doctor can remove them before they become cancerous.

limitations
Despite all its benefits, screening with the RSOSi test is not perfect.

In some cases, the test can detect blood in the stool when there is no cancer or polyp.

This situation is rare. About 1,000 people who take the test, about 15 people receive such a result. These few people then spend a long colonoscopy that is not necessary and can sometimes be removed polyps unnecessarily.

In addition, long colonoscopy can lead to some complications. To learn more, visit the Long Colonoscopy page.

On the contrary, people who have colorectal cancer can receive a normal test result.

This situation occurs for about 20% of people who have colorectal cancer. Their cancer has gone unnoticed. Indeed, no screening test, even long colonoscopy, can guarantee that a cancer will be detected. Therefore, it is recommended to repeat the RSOSi test every 2 years as this increases the chances that the cancer will be detected.
In addition, screening can detect cancer when it is at an early stage, increasing the chances of recovery. However, a number of people die each year from colorectal cancer, even if they had been screened.

Some numbers
Of 1,000 people who take the FOBT test, 36 will receive an abnormal test result and will have a long colonoscopy. Of these 36 people:

4 will have colorectal cancer;
17 will have one or more polyps removed;
15 will have no cancer or polyps.