Colorectal cancer | Detection and treatment

Detecting and treating colorectal cancer

Screening tests for colorectal cancer include stool tests that check for signs of cancer in a stool sample. Tests like a sigmoidoscopy and colonoscopy use a lighted scope to view part or all of the colon. A CT colonography, also called virtual colonoscopy, uses X-rays to view the colon.

Visits with your healthcare provider, including regularly scheduled screenings, are vital to monitoring your health and ensuring intervention when it is needed.

Colon Cancer: Screening Tests and What the Results Mean

Who should be screened for colorectal cancer?

Your risk for colorectal cancer gets higher as you get older. Some experts say that adults should start regular screening at age 50 and stop at age 75. Others say to start before age 50 or continue after age 75. Talk with your doctor about your risk and when to start and stop screening.

How often you need screening depends on the type of test you get:

  • Stool tests
    • Every year for FIT or gFOBT.
    • Every 3 years for sDNA, also called FIT-DNA.
  • Tests that look inside the colon
    • Every 5 years for CT colonography (virtual colonoscopy).
    • Every 10 years for colonoscopy.

Experts agree that people at higher risk may need to be tested sooner and more often. This includes people who have a strong family history of colon cancer. Talk to your doctor about which test is best for you and when to be tested.

How is colorectal cancer diagnosed?

If your doctor thinks you may have colorectal cancer, your doctor will ask you questions about your medical history. You may also have a physical exam. Other tests may include:

  • A colonoscopy. Your doctor uses a lighted scope to view the inside of your entire colon.
  • A biopsy. A sample of tissue taken from inside your colon. This may be done during your colonoscopy. Or a needle biopsy may be done to check for cancer in another part of your body.
  • Blood tests, such as a complete blood count (CBC). These may be used to find the cause of symptoms like weakness, anemia, or weight loss.
  • Imaging tests, such as a CT scan. These may be done to see if you have cancer in other places in your body.

How is colorectal cancer treated?

Physician talking to elderly couple with a tablet

Treatment for colorectal cancer is based on the stage and location of the cancer. It's also based on other things, such as your overall health. The main treatments are:

  • Surgery  In most cases, the doctor removes part of the colon or rectum and sews the healthy ends back together. Sometimes a small area of cancer can be removed during a colonoscopy.
  • Chemotherapy  These medicines kill fast-growing cells, including cancer cells and some normal cells. They may be given after surgery to help destroy any cancer cells that remain.
  • Radiation therapy  This uses high-dose X-rays to destroy cancer cells and shrink tumors. It may be combined with surgery. Chemotherapy and radiation may be given together. This is called chemoradiation.

In some cases, targeted therapy or immunotherapy may be an option. A clinical trial may be a good choice. Your doctor will talk with you about your options and then make a treatment plan.