The United States Preventive Services Taskforce (USPSTF) recommends that everyone between the ages of 45–75 years should receive colon cancer screening.

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This article is about screening for colon cancer. It will briefly explain colon cancer and the diagnosis rates, the USPSTF 2021 screening recommendations, and how colon cancer screening typically happens.

Colon cancer is any cancer that affects the colon. The colon is the longest section of the large intestine. Colon cancer typically affects people who are at least 50 years old.

According to the American Cancer Society, 95,520 people in the United States received a colon cancer diagnosis in 2017. There were also 39,910 diagnoses of rectal cancer.

Read about colorectal cancer here.

Colon cancer screening is when doctors test an individual for colon cancer, even if they do not have any symptoms. The purpose of colon cancer screening is to detect colon cancer early.

In 2016, the USPSFT made evidence-based recommendations about colon cancer screening. Their main recommendations were the following:

  • Doctors should screen all people between the ages of 50–75 years.
  • Doctors should screen anyone between the ages of 76–85 years if they request the screening themselves.
  • Doctors should discontinue screening for people over 85, even if they request it.

In 2021, after commissioning several studies into the effectiveness of colon cancer screening, the USPSTF updated its recommendations. The update was necessary because colorectal cancer is becoming more common in people under 50.

The 2021 USPSTF recommendations for colon cancer screening include all the USPSTF 2016 recommendations. However, the USPSTF now also recommends that healthcare professionals screen everyone between the ages of 45–49 years.

The 2016 USPSTF statement explains that doctors use several methods for screening for colon cancer. These include stool-based tests and imaging techniques.

The stool-based tests are the high sensitivity guaiac fecal occult blood test (gFOBT) and fecal immunochemical test (FIT). Their function is to detect blood in stool samples. The USPSTF recommends that eligible individuals receive a gFOBT or FIT yearly.

Other stool-based tests detect cancer biomarkers in stool samples. Cancer biomarkers are chemicals that the body releases in response to cancer. The colon can shed these cancer biomarkers into a person’s stool.

The USPSTF recommends that eligible individuals receive a stool DNA-FIT (sDNA-FIT) every 3 years. This looks for colon cancer biomarkers in stool samples.

Colonoscopy and sigmoidoscopy

If an individual has an abnormal stool-based test result, the USPSTF recommends a colonoscopy.

However, the UDPSTF also recommends a colonoscopy every 10 years, even without abnormal stool test results. A colonoscopy is when doctors use a thin, flexible tube to insert a camera into the colon. This allows doctors to obtain pictures of the colon, which can help detect any abnormalities.

Doctors can also use a flexible sigmoidoscopy to take pictures of the colon. This technique is similar to a colonoscopy, except it cannot reach as deep into the colon. In eligible individuals, the USPSTF recommends a flexible sigmoidoscopy every 5 years.

The USPSTF also recommends that eligible individuals receive a CT colonography every 5 years. This noninvasive technique uses a CT scan to visualize the inside of a person’s colon.

If a person has an abnormal flexible sigmoidoscopy or CT colonography result, the UDPSTF recommends a colonoscopy.

Learn more about alternatives to colonoscopy.

A 2022 review notes that while FIT may detect colon cancer in up to 88% of cases, sDNA tests can do so in up to 95% of cases.

Imaging techniques also vary in their capacities. CT colonography may only detect 67% of colon cancers, while colonoscopies may detect up to 92%.

Doctors may use other diagnostic tests for colon cancer. This includes performing a biopsy of any suspected colon tumors, which is necessary for a certain diagnosis.

Other techniques can help stage an individual’s colon cancer after the initial diagnosis. Such tests may include a chest, pelvic, and abdominal CT scan. They might also include an MRI scan of the liver.

These imaging techniques allow doctors to determine whether cancer has spread.

Colon cancer is a common form of cancer. It is becoming more common in people under 50 years old.

As of 2021, the USPSTF recommends regular colon cancer screening for everyone between the ages of 45–75 years.

There are various screening methods for colon cancer, such as gFOBT, sDNA-FIT, colonoscopy, sigmoidoscopy, and CT and MRI scans.