10/08/2024
By Steven Gorelick, , System Chair of the Digestive Health Institute, Nuvance Health System Chair of the Digestive Health Institute, Nuvance Health
When it comes to colorectal cancer, early detection is key. Currently, two primary categories of testing are available as screening methods; these are at-home tests and a colonoscopy exam. Let's explore the differences between these two tests so that you can make the best choice for your health.
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What is colorectal cancer?
Colorectal cancer is a disease that starts in your colon or rectum, often beginning as small, noncancerous growths called polyps that can turn cancerous over time. Colorectal cancer is one of the most common cancers worldwide. In the U.S., it ranks as the third most common cancer in both men and women. The American Cancer Society estimates there will be 106,590 new colon cancer cases in the U.S. by the end of 2024.
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Despite these alarming numbers, early detection significantly improves your chances of treatment and successful outcomes. That is why gastroenterologists recommend regular colorectal cancer screenings to detect abnormal polyps before they develop into cancer.
Related content: What are the symptoms of colorectal cancer?
Colonoscopy: The ‘gold standard’ for screening
Colonoscopy is considered the most effective screening method for colorectal cancer by almost all international and national gastroenterology and cancer societies. It allows doctors to examine the lining of your colon and rectum to spot any abnormalities such as pre-cancerous polyps.
During the procedure, a long, flexible tube with a camera called a colonoscope is inserted through your rectum and guided through your colon. In this respect it is not only a test that serves as screening for cancer but is the only test that has been proven time and time again to prevent colon cancer.
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The benefits of a colonoscopy are significant because it allows your doctor to see and immediately remove any polyps or abnormal growths, reducing your risk of colon cancer.
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The procedure does require a bowel cleansing beforehand so the gastroenterologist can fully evaluate the lining of the colon.
Risks of complications are rare and the likely hood of your doctor discovering a precancerous polyp is much greater than any problem occurring with the exam making colonoscopy the ‘gold standard’ and best method for screening and preventing colon cancer.
Learn more about colonoscopies in this video: See what it’s like to get a colonoscopy screening
The American Cancer Society recommends that people at average risk of colorectal cancer start regular colonoscopy screenings at age 45. If you have a family history of colorectal cancer or other risk factors, your doctor may recommend starting earlier.
At-home tests: A non-invasive alternative
At-home tests offer a non-invasive alternative for colorectal cancer screening. This simple stool-based test analyzes DNA and blood biomarkers to detect cancer or pre-cancerous advanced polyps from your own home.
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At-home tests are a convenient option with a high sensitivity for detecting cancer and advanced polyps — studies show it’s more than 90% accurate. However, if the test result is positive, a follow-up colonoscopy is needed to confirm the findings.
At-home tests, however, are far from perfect and will miss a large percentage of earlier precancerous polyps. While this test may be used to detect colon cancer it is not recommended for this reason as the first option by gastroenterologist for prevention of cancer.
Learn more about the Digestive Health Institute at Nuvance Health.
This test is recommended for individuals at average risk for colorectal cancer between the ages of 45 and 75. Those with a prior history of polyps or a family history of polyps or cancer would not be eligible for this method of testing. Your doctor should help determine whether at-home tests are the right test for you.
Comparing at-home tests and colonoscopy screenings
When deciding between at-home tests and colonoscopy screenings it’s important to understand their key differences.
- At-home test is a non-invasive stool test that detects genetic mutations and abnormal DNA linked to colorectal cancer. You can do it at home and there is no need for special preparation or dietary restrictions. However, it’s not as accurate as a colonoscopy and some early-stage cancers or precancerous polyps may not appear on the results of the test. There are false positives and negatives associated more often with this method of testing. The test is performed every two to three years depending on recommendations from your doctor.
Related content: Is someone being a pain in the butt about colonoscopy screenings? Here is what to say to them.
- Colonoscopy is a more thorough test, allowing your doctor to directly examine your colon and remove polyps at the time of your procedure rather than during a follow-up appointment. This method is the ‘gold standard’ for colorectal cancer screening because it can both detect and prevent cancerous polyps. It does require preparation, which can be uncomfortable, but worth it to prevent colorectal cancer or detect it early before it spreads. Colonoscopy screenings are safe and effective; over 15 million colonoscopies are performed annually in the U.S. If your colonoscopy test turns up negative it is repeated every 10 years.
Choosing a colorectal screening method
Choosing the right colorectal cancer screening method is important for your health. Talking with your doctor is the best way to understand your options and get personalized recommendations.
Be sure to discuss your risk factors — such as age, family history and lifestyle choices — and your preferences.
Regular screening is key to catching and preventing colorectal cancer early. At-home tests are non-invasive while colonoscopy offers a comprehensive examination in a medical setting and is the preferred ‘gold standard’ test.
The bottom line: Colonoscopies are the gold standard for colorectal cancer screening due to their ability to detect and remove polyps early and during the procedure. At-home tests are a non-invasive alternative that can be done in the comfort of your own home but may require a follow-up appointment with your doctor if results are positive. Discuss our options with your doctor and choose the most suitable method for colorectal cancer screening based on your individual health factors and needs.
Learn more about colorectal cancer at the Nuvance Health Cancer Institute.