Screening Methods for Colorectal Cancer
Sometimes abnormal growth, known as polyps, forms in the rectum or colon. As time passes, few polyps may convert into cancer.
Screening tests can determine polyps so they can be removed before becoming cancer.
Screening also determines colorectal cancer at an early stage, when treatment functions best. However, many people in Pune are confused about which screening test is most suitable.
So, let us first start by understanding what a colorectal cancer screening is.
What Is Colorectal Cancer Screening?
A screening test finds for a disease when someone does not have symptoms. (When someone has symptoms, diagnostic tests are used to bring out the symptom’s cause.)
Colorectal cancer always forms from precancerous polyps (abnormal growths) in the rectum or colon. Screening tests can determine the precancerous polyps. Hence, a specialist can remove them before they become cancer.
Screening tests also find colorectal cancer at an early stage, when treatment works best.
Colorectal Cancer Screening Guidelines
Frequent screening, starting from age fifty, is the key to avoiding colorectal cancer. Many studies suggest that adults age fifty to seventy-five must be screened for colorectal cancer.
You can go for various colorectal cancer screening methods, including:
- Stool tests
- Colonoscopy
- Flexible Sigmoidoscopy
- CT colonography (virtual colonoscopy)
Now that you are aware of the various tests let us discuss when should you begin screening
When Should I Begin to Get Screened?
It would be best if you began screening for colorectal cancer right after turning fifty. You may continue screenings at regular intervals. In some cases, you may require tested earlier than fifty, or more often than others, when –
- You or a relative have had colorectal cancer or colorectal polyps.
- You have an inflammatory bowel disease like ulcerative colitis or Crohn’s disease.
- You got a genetic syndrome like hereditary non-polyposis colorectal cancer (Lynch syndrome) or familial adenomatous polyposis (FAP)external icon
- If you feel you are at higher risk for colorectal cancer, consult your doctor regarding—
- When to start screening.
- Which test for you is correct?
- How usually to have tested.
Many screening tests can be used to determine colorectal cancer or polyps. Let us look into some of the screening tests involved.
Stool Tests
Some of the stool tests include:
- Guaiac-based fecal occult blood test (gFOBT)
It utilizes the chemical guaiac to identify blood in the stool. It is performed once a year. For the test, you get a test kit from your health care provider. At home, you use a brush or stick to acquire a small quantity of stool. You return the test kit to your doctor or a lab. There the stool samples are analyzed for the blood’s presence.
- Fecal immunochemical test (FIT)
It utilizes antibodies to identify blood in the stool. It is performed once a year in the same procedure as a gFOBT.
- FIT-DNA test
It is also known as the stool DNA test. It combines the FIT with a test that identifies altered DNA in the stool. For the test, you gather a full bowel movement and give it to a lab. There it is analyzed for cancer cells. It is performed once every one or three years.
Flexible Sigmoidoscopy
For this test, the specialist puts a thin, short, lighted, flexible tube into your rectum. The doctor looks for cancer or polyps within the rectum and lower third of the colon.
How often: Every five years, or every ten years with a FIT each year.
Colonoscopy
It is similar to flexible sigmoidoscopy, except the specialist uses a longer, lighted, thin, flexible tube to look for polyps or cancer with the rectum and the whole colon. At the test, the specialist can find and remove several polyps and a few cancers.
Colonoscopy also is done as a follow-up test if something unusual is found at one of the other screening tests.
How often: Every ten years (for individuals who do not have a higher risk of colorectal cancer).
CT Colonography (Virtual Colonoscopy)
Computed tomography (CT) colonography is also known as virtual colonoscopy. It uses computers and X-rays to create images of the whole colon. The images get displayed on a computer screen for the specialist to examine.
How often: Every five years.
There is no one “best test.” Every test has merits and demerits. Discuss with your gastroenterologist in Pune about every test’s advantages and disadvantages and how often to be tested.