Is Fit stool test as good as colonoscopy?
While cancer detection rates may be nearly equivalent between FIT-fecal DNA and colonoscopy, colonoscopy is the clear choice for advanced polyp detection and removal before cancer is established.
But a normal FIT result doesn't completely rule out cancer. Some people can have cancer and a normal FIT result. It's important to go back to your GP if your symptoms continue, change, or get worse even if you have normal test results. Some people will need to have further tests.
The FIT test
It exhibited a sensitivity of 12.9%-79.4% with a specificity of 86.7%-97.7% for CRC screening in many studies[6-13].
Colonoscopy is one of the most sensitive tests currently available for colon cancer screening. The doctor can view your entire colon and rectum. Abnormal tissue, such as polyps, and tissue samples (biopsies) can be removed through the scope during the exam.
However, I repeated my FIT and received a normal result. Does this mean that I don't need a colonoscopy? The Colon Screening Program recommends that all abnormal FIT results be followed up with a colonoscopy. Even if the second test is normal, the Colon Screening Program recommends follow-up colonoscopy.
FIT detects signs of colon and rectal cancer. It can also detect some polyps, which are growths that could become cancer later. HOW? You will get a kit from your provider or in the mail with instructions about how to take a sample of stool.
FIT has a false positive rate of about 5%, which again, needs to be followed up with a colonoscopy. The tier 2 test, the FIT-Fecal DNA Test, is designed to detect microscopic blood as well as abnormal DNA in stool samples.
Among non-compliers, 882 CRC were diagnosed overall (3.77%), 659 of which were colon cancers (74.7%) and 204 were rectum cancers (23.1%). The proportion of CRC diagnosed <1 year after the positive FIT was significantly higher among compliers (90.1%) than among non-compliers (62.9%, (p<0.0001).
Which patients are eligible for FIT? Faecal occult blood tests should not be offered patients, with an abdominal or rectal mass, rectal bleeding, anal ulceration or if they are age >60 y with iron deficiency anaemia.
Cologuard is better at detecting cancer than FIT (92% vs 74% for FIT), but the false positive rate is higher. Cologuard has a 13% false-positive rate, and that rate increases as people age. Cologuard is less accurate than a colonoscopy at detecting polyps of any size.
What is the gold standard for colon cancer screening?
Your Colorectal Cancer Screening Choices
The gold standard for screening, a colonoscopy, only needs to be done once every 10 years for people at average risk if no precancerous changes are found.
52% of faecal immunohistochemistry test (FIT)-positive clients in the Irish National Colorectal Cancer Screening Programme (BowelScreen) have adenomatous polyps identified at colonoscopy in round 1.
Early symptoms of colon cancer might include blood in the stool; persistent problems in defecating (long-lasting diarrhea or constipation); feelings of cramping, distension or pain in the area of the bowel; or a persistent decrease in the size of the stool.
Stool based tests, such as Cologuard or FIT, are reasonable alternatives for patients who are unable or unwilling to undergo a standard colonoscopy. Screening saves lives. Talk to your doctor about the appropriate colon cancer screening option for you.
Stool tests can produce false positive and false negative results. A false positive test would occur when the test was positive but you do not have any signs of polyps or cancer. This happens approximately 25% of the time.
False-positive (FP) results of fecal immunochemical tests (FITs) conducted in colorectal cancer (CRC) screening could lead to performing unnecessary colonoscopies. Hemorrhoids are a possible cause of FP FIT results; however, studies on this topic are extremely rare.
There may be a number of di erent reasons why blood was found in your stool, including ulcers, hemorrhoids (sometimes painless or internal), anal fissures, diverticular disease, or inflammation.
Quantitative FIT can measure the concentration of hemoglobin in feces by using an antibody that targets human hemoglobin. Fcal estimates the degree of inflammation in the gut based on the amount of infiltrating inflammatory cells, whereas FIT measures the amount of blood hemorrhaging from the intestinal mucosa.
A positive FIT test will tell your doctor that you have bleeding occurring somewhere in your gastrointestinal tract. This blood loss could be due to ulcers, bulges, polyps, inflammatory bowel disease, haemorrhoids (piles), swallowed blood from bleeding gums or nosebleeds, or it could be due to early bowel cancer.
You use a home test kit, called a faecal immunochemical test (FIT), to collect a small sample of poo and send it to a lab. This is checked for tiny amounts of blood. Blood can be a sign of polyps or bowel cancer. Polyps are growths in the bowel.
What is a high score on a FIT test?
The higher the FIT value is above 20 the greater is the likelihood that there are polyps or a malignancy. FIT is also positive in patients with IBD as you would expect.
Two days before and the day of the fecal occult blood test, cut out all red meat, beets, broccoli, cantaloupe, carrots, cauliflower, cucumbers, grapefruit, horseradish, mushrooms, radishes, and turnips, which can all trigger false alarms. Schedule dental work after the test.
An abnormal FIT result could mean you have colorectal cancer, even if you feel healthy or no one else in your family has the disease. Even if you have had normal FIT results in the past, a new abnormal result means something in your colon may have changed and you need a colonoscopy to find out more.
Delays to colonoscopy of over 9 mo after positive FIT were significantly associated with higher incidence of CRC and advanced stage of CRC at diagnosis (compared with performing colonoscopy within 1 mo). AOR, adjusted odds ratio; CI, confidence interval; CRC, colorectal cancer; FIT, fecal immunochemical test.
It's possible for a stool DNA test to show signs of cancer, but no cancer is found with other tests. Doctors call this a false-positive result. It's also possible for the test to miss some cancers, which is called a false-negative result. Having a stool DNA test may lead to additional testing.