Regenstrief Institute Finds Fecal Immunochemical Test May Be as Effective as Colonoscopy at Detecting Colorectal Cancers
Doctors may begin ordering FITs in greater numbers, increasing the demand on clinical laboratories to process these home tests
All clinical laboratory managers and pathologists know that timely screening for colon cancer is an effective way to detect cancer early, when it is easiest to treat. But, invasive diagnostic approaches such as colonoscopies are not popular with consumers. Now comes news of a large-scale study that indicates the non-invasive fecal immunochemical test (FIT) can be as effective as a colonoscopy when screening for colon cancer.
FITs performed annually may be as effective as colonoscopies at detecting colorectal cancer (CRC) for those at average risk of developing the disease. That’s the conclusion of a study conducted at the Regenstrief Institute, a private, non-profit research organization affiliated with the Indiana University School of Medicine in Indianapolis, Ind.
The researchers published their findings in the Annals of Internal Medicine (AIM), a journal published by the American College of Physicians (ACP). The team reviewed data from 31 previous studies. They then analyzed the test results from more than 120,000 average-risk patients who took a FIT and then had a colonoscopy. After comparing the results between the two tests, the researchers concluded that the FIT is a sufficient screening tool for colon cancer.
FIT is Easy, Safe, and Inexpensive
As a medical laboratory test, the FIT is low risk, non-invasive, and inexpensive. In addition, the FIT can detect most cancers in the first application, according to the Regenstrief Institute researchers. They recommend that the FIT be performed on an annual basis for people at average risk for getting colorectal cancers.
“This non-invasive test for colon cancer screening is available for average risk people,” Imperiale told NBC News. “They should discuss with their providers whether it is appropriate for them.”
FIT is performed in the privacy of the patient’s home. To use the test, an individual collects a bowel specimen in a receptacle provided in a FIT kit. They then send the specimen to a clinical laboratory for evaluation. The FIT requires no special preparations and medicines and food do not interfere with the test results.
‘A Preventative Health Success Story’
The FIT can be calibrated to different sensitivities at the lab when determining results. Imperiale and his team found that 95% of cancers were detected when the FIT was set to a higher sensitivity, however, that setting resulted in 10% false positives. At lower sensitivity the FIT produced fewer false positives (5%), but also caught fewer cancers (75%). However, when the FIT was performed every year, the cancer detection rate was similar at both sensitivities over a two-year period.
“FIT is an excellent option for colon cancer screening only if it is performed consistently on a yearly basis,” Felice Schnoll-Sussman, MD, told NBC News. Sussman is a gastroenterologist and Professor of Clinical Medicine at Weill Cornell Medicine. “Colon cancer screening and its impact on decreasing rates of colon cancer is a preventative health success story, although we have a way to go to increase rates to our previous desired goal of 80% screened in the US by 2018.”
The FIT looks for hidden blood in the stool by detecting protein hemoglobin found in red blood cells. A normal result indicates that FIT did not detect any blood in the stool and the test should be repeated annually. If the FIT comes back positive for blood in the stool, other tests, such as a sigmoidoscopy or colonoscopy should be performed. Cancers in the colon may not always bleed and the FIT only detects blood from the lower intestines.
Patients are Skipping the Colonoscopy
Approximately 35% of individuals who should be receiving colonoscopies do not undergo the test, NBC News noted. The American Cancer Society (ACS) lists the top five reasons people don’t get screened for colorectal cancer are that they:
- fear the test will be difficult or painful;
- have no family history of the disease and feel testing is unnecessary;
- have no symptoms and think screening is only for those with symptoms;
- are concerned about the costs associated with screening; and
- they are concerned about the complexities of taking the tests, including taking time off from work, transportation after the procedure, and high out-of-pocket expenses.
“Colorectal cancer screening is one of the best opportunities to prevent cancer or diagnose it early, when it’s most treatable,” Richard Wender, MD, Chief Cancer Control Officer for the ACS stated in a press release. “Despite this compelling reason to be screened, many people either have never had a colorectal cancer screening test or are not up to date with screening.”
Colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. The ACS estimates there will be 101,420 new cases of colon cancer and 44,180 new cases of rectal cancer diagnosed this year. The disease is expected to be responsible for approximately 51,020 deaths in 2019.
New cases of the disease have been steadily decreasing over the past few decades in most age populations, primarily due to early screening. However, the overall death rate among people younger than age 55 has increased 1% per year between 2007 and 2016. The ACS estimates there are now more than one million colorectal cancer survivors living in the US.
The ACS recommends that average-risk individuals start regular colorectal cancer screenings at age 45. The five-year survival rate for colon cancer patients is 90% when there is no sign that the cancer has spread outside the colon.
Clinical laboratory professionals may find it unpleasant to test FIT specimens. Opening the specimen containers and extracting the samples can be messy and malodorous. However, FITs are essential, critical tests that can save many lives.