Colorectal Cancer Screening Tests

Colorectal Cancer Screening Tests

Colorectal cancer is a serious disease, but there are screening tests available that can find it early for people who are at average risk. Early detection can allow for more treatment options, greater chances of successful therapy, and improved long-term outlook.

It's important to talk to your doctor about which test is right for you. Screening is recommended to begin at age 50, and earlier in some cases.

Preparation

Preparation depends on the type of screening test being done. Generally, you may be asked to stop taking certain medications, and/or eat a special diet for several days.

Procedure

Screening tests typically involve a swab of the rectum, a blood test, or an imaging test, such as a CT scan. Your doctor may also order other tests, such as a colonoscopy.

Types

• Fecal occult blood test - a sample of stool is tested for small amounts of blood that isn't visible to the naked eye.
• Sigmoidoscopy - a thin, flexible tube with a camera is inserted into the rectum and the lower portion of the colon is examined.
• Colonoscopy - a thin, flexible tube with a camera on the end is inserted into the rectum and the entire colon is examined.
• Flexible sigmoidoscopy and CT colonography (virtual colonoscopy) - an imaging test used to view the entire colon.
• Stool DNA test - a stool sample is tested for cancerous or precancerous cells.

Risks

Screening tests can involve risks. For example, a colonoscopy can cause a tear in the colon walls, and some medications used to prepare for the exam can cause allergic reactions. Talk to your doctor about any potential risks before having a screening test.

Why Screen?

Colorectal cancer is the third most common form of cancer in the world, and the second leading cause of cancer death in the U.S. Each year, approximately 140,000 people are diagnosed with colorectal cancer, and in 2015, 50,260 people died of the disease. Early detection and treatment are key to improving outcomes and survival.

When Should You Screen?

The U.S. Preventive Services Task Force recommends screening starting at age 50, and earlier for people with a family history of the disease. Talk to your doctor about when to start screening and which test is right for you.