The second leading cause of cancer deaths in the United States for both men and women is colon or colorectal cancer. Colon cancer is also one of the most treatable forms of cancer if detected early. Millions of lives have been saved each year due to colorectal cancer screening tests that can detect premalignant tissue growths known as polyps. Unfortunately, according to the CDC (Centers for Disease Control and Prevention), 1 in 3 adults between the ages of 50 to 75 are not getting screening for colorectal cancer every year. Why?
Many adults are not aware that they need to be screened for colorectal cancer and others avoid the screening because they are wary of a colonoscopy – the preferred method to screen for colorectal cancer. When people are given different options to test for colorectal cancer they are more likely to follow through with the screening. There are several alternative options to a colonoscopy that are effective in detecting colorectal cancer cells early. Each has their own advantages and disadvantages when comparing:
Also called CT (computerized tomography) colonography, a virtual colonoscopy uses a CT scanner to capture images of the colon and rectum. In this imaging procedure, a radiologist examines your rectum and colon from outside of your body with the use of x-rays and a computer. By looking at the images from several different angles, the radiologist can identify ulcers, polyps, and even cancer. A virtual colonoscopy is more cost-effective , less time-consuming, and less invasive than a colonoscopy. However, if a polyp is found during the imaging appointment, you will need to have a colonoscopy to have it removed.
Pros
Cons
Price: $250-$500
Invasiveness: Noninvasive but requires bowel preparation
Complications and Recovery: Low risk of complications and recovery simply is eating a good meal. Your doctor will inflate your colon with air before taking the xray. There is a small risk with the inflation that a perforation (tear or hole) may occur in the lining of the large intestine.
Accuracy and ability to diagnose: 90% effective in finding larger tumors and 65% effective at detecting tumors measuring ½ centimeter or larger
Like the virtual colonoscopy, a double-contrast barium enema uses X-rays to identify abnormal tissue in the lining of the colon. Barium is a silver-white metallic compound that is coated along the walls of the intestinal lining to assist visualization of the colon and rectum with the use of an enema tube. After the large intestine is coated with the barium, air is passed into the colon through the rectum to inflate the colon to enhance imaging. The physician will take x-rays from several different angles of the colon as the barium and air fill the intestine to help identify abnormalities, such as polyps, abnormal tissues, and lesions.
Pros
Cons
Price: $200-$1000
Invasiveness: Moderate
Complications and Recovery: Low risk for perforation and a faster recovery than a colonoscopy due to no sedation needed
Accuracy and ability to diagnose: Less sensitive than colonoscopy in detecting polyps and tumors
FIT uses antibodies to detect the blood protein globin found in hemoglobin. These tests are designed to detect specifically human globin proteins and will not react with blood proteins from non-human blood that is found in red meats. People who take the FIT to screen for colorectal cancer do not need to avoid red meats and other foods or medications before they take the test.
Pros
Cons
Price: $20
Invasiveness: Noninvasive
Complications and recovery: Very low risk for complication and no recovery time
Accuracy and ability to diagnose: Detects nearly 80% of colon cancers. There are false negative and false positive results returned to some patients.
Like FIT, this test checks your stool for occult blood, or blood you cannot see by looking at your stool. In this test, you need to collect stool samples for 3 consecutive days. The reason for this is to increase the possibility of finding blood, as the bleeding may not be occuring every day. The FOBT does have food, supplement, and medication restrictions.
Pros
Cons
Price: $25
Invasiveness: Noninvasive
Complications and recovery: Very low risk for complication and no recovery time
Accuracy and ability to diagnose: 71%-95% effective in detecting cancer cells
The Cologuard home colon cancer screening test detects cancer by identifying DNA markers and occult blood in stool samples. You are not required to change your diet or medications before this test. Once you collect a sample of your stool, you will send or drop off your sample to a lab. The lab will return the results to your physician or healthcare provider who will contact you as soon as they arrive.
Pros
Cons
Price:$500-$600
Invasiveness: Noninvasive
Complications and recovery: Very low risk for complication and no recovery time
Accuracy and ability to diagnose: Detects 92% of colorectal cancers
In a sigmoidoscopy, a physician examines the rectum and the distal or “left” side of the colon, using a flexible tube with a camera equipped on one end. A sigmoidoscopy is cheaper and less invasive than a colonoscopy but does reach the proximal or “right” side of the colon. Because a sigmoidoscopy only examines the lower section of the colon, the procedure takes much less time and patients usually choose to not be sedated. If the examining physician finds a polyp or abnormal tissue in the sigmoid they will promptly remove the polyp and test the tissue for malignancy.
Pros
Cons
Price $200 -$300
Invasiveness Moderate
Complications and Recovery
Accuracy and Ability to Diagnose
Centers of Disease Control and Prevention. (2013, November 05). Colorectal cancer tests save lives. Retrieved from CDC Vital Signs: https://www.cdc.gov/vitalsigns/colorectalcancerscreening/index.html#problem
Fletcher, J. (2020, June 04). 7 alternatives to a colonoscopy. Retrieved from Medical News Today: https://www.medicalnewstoday.com/articles/320132
Mayo Clinic Staff. (2020, May 06). Flexible sigmoidoscopy. Retrieved from Mayo Clinic: https://www.mayoclinic.org/tests-procedures/flexible-sigmoidoscopy/about/pac-20394189
National Institutes of Health. (2008, September). Virtual colonoscopies rival accuracy of standard ones. Retrieved from NIH: https://www.nih.gov/news-events/nih-research-matters/virtual-colonoscopies-rival-accuracy-standard-ones
Nemo, L. (2021, March 25). How at-home colorectal cancer screening tests compare to coloscopies. Retrieved from Discover Magazine: https://www.discovermagazine.com/health/how-at-home-colorectal-cancer-screening-tests-compare-to-colonoscopies
Norton Healthcare. (2020, October 06) Is an at-home colon cancer test right for? Retrieved from Norton Healthcare: https://nortonhealthcare.com/news/at-home-colon-cancer-test/
Pickhardt, P. J. (2007, August). Screening CT Colonography: How I do it. American Journal of Roentgenology, 189, 290-298. Retrieved from AJR Online: https://www.ajronline.org/doi/pdf/10.2214/AJR.07.2136
Ramdzan, A. R., et., al. () Diagnostic accuracy of FOBT and colorectal cancer genetic testing: A systematic review & meta-analysis. Annals of Global Health, 70. Retrieved from Annals of Global Health: https://annalsofglobalhealth.org/articles/10.5334/aogh.2466/
