If you are in your mid-40s or older, chances are you’ve seen ads for do-it-yourself home screening tests for colorectal cancer. You may even have received information about them from your health insurance company.
And if you’re anxious about having your first colonoscopy, you may be wondering if they work and whether you should try one.
The answer to both questions, according to Anand Kishore, M.D., with Carilion Clinic Gastroenterology, is it depends.
"These tests are easy to do at home," he said, "but they are not as accurate as colonoscopy."
In addition, home tests are not appropriate for everyone. "There may be some dietary and medication restrictions," said Dr. Kishore. "Some of these tests are not recommended for high-risk individuals."
About Colorectal Cancer
Colorectal cancer is the fourth leading cause of death worldwide and the third most common cancer (aside from skin cancers) diagnosed in both men and women in the U.S. The American Cancer Society predicts about 150,000 new cases of colon and rectal cancers combined in 2021.
Risk factors for colorectal cancer include:
- Personal and family history
- Certain gastrointestinal conditions
- Certain genetic syndromes
"Obesity is also a risk factor," said Dr. Kishore, "and weight modification and exercise do help."
The rate of new diagnoses is on the decline overall thanks to more older adults being screened. But it’s still rising among those in the under-50 and under-65 groups—those who should be getting their first colonoscopy. The American Cancer Society recommends that people of average risk for colon cancer begin regular screening at age 45.
About Home Testing
The coronavirus pandemic has both patients and providers taking a close look at opportunities for home testing and digital connections to care wherever possible. This includes home-based stool sample kits, which require a small sample that you collect yourself and mail to the company’s lab in their packaging.
The three types approved by the U.S. Food and Drug Administration for home testing are:
- Guaiac FOBT (gFOBT), which can detect a component of hemoglobin
- Fecal immunochemical tests (FIT or iFOBT), which use antibodies to detect hemoglobin shed by polyps or colorectal cancer
- Multitarget stool DNA tests (FIT-DNA), which detect trace amounts of blood and DNA from cancer cells
A review published in the Journal of the American Medical Association found that all three home tests may be an efficient first-step screening for low-risk patients. However, Dr. Kishore noted several drawbacks:
- They can return false positives and false negatives
- They cannot remove polyps
- Smaller polyps may not detected
- Some of the home tests need to be done more frequently
And ultimately, if the lab detects abnormal results, it will recommend a colonoscopy, which remains the gold standard for screening-and-treatment-in-one.
Unlike many screening procedures, a colonoscopy does not just detect cancer—your gastroenterologist also removes 98 percent of precancerous and cancerous polyps during the procedure.
To prepare for your colonoscopy, you will drink a laxative that clears your colon. While this makes some people wary, the procedure is painless, takes less than half an hour and is typically good for 10 years.
Carilion Clinic Gastroenterology supports the ACS recommendations that most people begin colorectal cancer screening at age 45. Colonoscopies remain as safe as they are effective. Carilion Clinic has implemented safety precautions in response to the coronavirus pandemic that make getting your colonoscopy as safe as ever.
- Eat lots of vegetables, fruits and whole grains
- Minimize processed meats like hot dogs, and eat less red meat overall
- Get regular exercise
- Take control of your weight
- Don’t smoke—and quit now if you do
- Avoid alcohol, or limit it to one (women) or two (men) drinks a day