Cedars-Sinai Blog

At-Home Colorectal Cancer Screening: What You Should Know

What people should know about at-home colorectal cancer screening test kits

Colorectal cancer causes an estimated 50,000 deaths annually. But it's also one of the most treatable forms of cancer—if detected early.

In fact, in many cases, screening can prevent the disease from developing.

"Healthcare authorities, such as the American Cancer Society and the U.S. Preventive Services Task Force, recommend people at an average risk of colorectal cancer begin colon cancer screening exams at age 45 and up," says Dr. Derek Cheng, a gastroenterologist at Cedars-Sinai.

"The best screening test is the one that gets done. So, if people aren't willing to undergo a colonoscopy, we still want them to consider the at-home testing options."

Unfortunately, only about half of Americans stick to the recommended screening schedule. One reason for the low uptake: The gold standard screening exam, a colonoscopy, requires a somewhat unpleasant "bowel prep" that involves fasting for hours and taking a powerful bowel-clearing substance. Other obstacles include the fear of undergoing sedation, needing to take time off of work and not being able to drive yourself to and from the exam.

But colorectal cancer screening test kits are beginning to create an uptick in screening rates. These tests are safe, effective and require almost zero pre-test prep. Plus, you can do them from the comfort of your home.

At-home screening options

Dr. Derek Cheng, a gastroenterologist at Cedars-Sinai

Derek Cheng, MD

Every day, your colon sheds cells that line the colon into the stool, so at-home stool collection tests can often uncover cancerous changes. For those who can't or won't do the bowel prep necessary for a colonoscopy, at-home testing kits are somewhat successful at detecting early colon cancer lesions. And studies suggest these fecal blood tests are associated with increased screening rates.

While the Food and Drug Administration (FDA) has approved three types of at-home colon cancer screening tests, only two are in wide use for their ease and effectiveness. Patients can request the test they want, but it's important to note that not every at-home kit is covered by insurance.

  • FIT: The fecal immunochemical test, or FIT, uses antibodies to detect blood in the stool, and it's about 79% accurate at detecting colon cancer. All you have to do: Have a bowel movement, collect a small amount of fecal matter and send it to the lab for analysis. The kit includes everything you need from instructions and a swab for fecal collection to a sterile container and special envelope for mailing. FIT is simple, seamless and covered by most insurance companies.
    The drawbacks: Since polyps may not be bleeding at the time of testing, and the test relies on blood in the stool to detect cancer, patients need to repeat FIT annually. And if the FIT test comes back positive, you still need a colonoscopy. Another drawback: "The FIT test is prone to false positive, and a positive result warrants additional investigation through a colonoscopy," Dr. Cheng says.
  • Cologuard: A pricier option than FIT, Cologuard is about 92% accurate at detecting colorectal cancer. "In addition to looking for blood in the stool, like FIT, Cologuard also searches for DNA markers of colon cancer and precancerous polyps," Dr. Cheng says.
    The drawbacks: Cologuard testing needs to be repeated every three years, and not all Cologuard tests are covered by insurance.

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.

"If an at-home test comes back positive, patients still need to undergo a colonoscopy, not only to diagnose cancer, but also to remove polyps and prevent cancer," Dr. Cheng says. 

Becoming savvy about colon cancer screening

There's no debate that colonoscopy is still the most effective screening exam for colon cancer. The first-rate exam not only detects colon cancers with about 98% accuracy, but it also allows doctors to remove precancerous and cancerous polyps during the procedure. But patients now have other options.

"The best screening test is the one that gets done," says Dr. Cheng. "So, if people aren't willing to undergo a colonoscopy, we still want them to consider the at-home testing options."

Certain lifestyle habits can increase your risk of developing colon cancer, including smoking, heavy drinking, physical inactivity and poor dietary habits. If you have a family history of the disease or regularly engage in habits that can harm your colon, talk to your doctor about initiating colon cancer screening before age 50.