Colorectal cancer is the second leading cause of cancer death in the United States. Every year, 50,000 deaths occur due to colon cancer, but it is one of the most treatable forms of cancer if detected early.
“The COVID-19 pandemic has caused many people to delay important screenings or delay visiting their healthcare provider,” said Dr. Harbir Sawhney, gastroenterologist at Baystate Gastroenterology- Palmer. “But health screenings are vital to good health.”
Colorectal cancer screenings are important because they can find precancerous polyps and abnormal growths, and in many cases can prevent the disease from developing.
“A colonoscopy is considered the gold standard for testing for colorectal cancer. The procedure not only detects colon cancers with about 98% accuracy, but it allows doctors to remove precancerous and cancerous polyps during the procedure,” said Dr. Sawhney. “While a colonoscopy is one of the most sensitive tests available for colon cancer screening, there are several other screening tests for colorectal cancer. Each patient should talk to their primary care provider about the pros and cons of each test and which is right for them.”
At-Home Colon Cancer Tests
Stool-Based Tests
These tests look at the stool (feces) for possible signs of colorectal cancer or polyps. They are typically done at home, so many people find them easier than tests like a colonoscopy. But these tests need to be done more often, and if the result from one of these stool tests is positive (abnormal), you will still need a colonoscopy to see if you have cancer.
Fecal Occult Blood Test
The guaiac-based fecal occult blood test (gFOBT) uses the chemical guaiac to detect blood in the stool. It is done once a year. For this test, you receive a test kit from your healthcare provider. You return the test kit to the doctor or a lab, where the stool samples are checked for the presence of blood. How often: This screening test is done once a year.
FIT Test
A fecal immunochemical test (FIT) uses antibodies to detect blood in the stool. How often: It is also done once a year in the same way as a gFOBT test.
Cologuard (FIT-DNA Test)
The FIT- DNA test, also referred to as a stool DNA test, combines the FIT with a test that detects altered DNA in the stool. For this test, you collect an entire bowel movement and send it to a lab where it is checked for cancer cells. How often: a FIT-DNA test should be done every three years.
Cologuard is a stool DNA test that detects DNA mutations and detects precancer and cancer, if present, from a full stool sample. It is a non-invasive test that can be done from home and then mailed out to a lab for analysis. If you’re taking the Cologuard test, you will receive a home screening kit that includes all that you need to collect a stool sample.
How Often: A Cologuard test is recommended every 3 years and not all Cologuard tests are covered by insurance.
What to Do
To do at-home colon cancer screening, you'll need a prescription from your doctor. You'll collect the sample at home with the prescribed kit, then mail it off to the prescribing doctor (or a lab). When the analysis is complete, your doctor will go over the results with you.
Visual (Structural) Colon Cancer Tests
These tests look at the inside of the colon and rectum for any abnormal areas that might be cancer or polyps. These tests can be done less often than stool-based tests, but they require more preparation ahead of time, and can have some risks not seen with stool-based tests.
Flexible Sigmoidoscopy
For this test, the doctor puts a short, thin, flexible, lighted tube into your rectum. The doctor checks for polyps or cancer inside the rectum and lower third of the colon. How often: Every 5 years, or every 10 years with a FIT every year.
Colonoscopy
This is like flexible sigmoidoscopy, except the doctor uses a longer, thin, flexible, lighted tube that has a small video camera on the end to check for polyps or cancer inside the rectum and the entire colon. During the test, the doctor can find and remove most polyps and some cancers. Colonoscopy is also used as a follow-up test if anything unusual is found during one of the other screening tests. How often: Every 10 years (for people who don’t have an increased risk of colorectal cancer).
“If any of the stool screening tests result in a positive finding, that is if hidden blood is found, a colonoscopy will need to be done to investigate further,” said Dr. Sawhney.
“Although blood in the stool can be from cancer or polyps, it can also be from other causes, such as ulcers, hemorrhoids, or other conditions."
Screening for colon cancer is an important step in the prevention of colon cancer. Talk to your primary care provider about the pros and cons of each test and which is right for you.
Learn More About Colon Cancer Screening
Colorectal cancer is the second leading cause of cancer-related deaths in U.S. adults. But it’s also among the most treatable cancers when it’s caught early. Learn more about colorectal cancer screening.