Testing for colon cancer can be important before you ever notice any warning signs. Sudden weight loss, blood in the stool, or bowel changes are noticeable symptoms that cancer has already advanced.
Colorectal cancer, called colon cancer for short, is a malignant condition that occurs when there’s abnormal cell growth in the colon or rectum.
Most colon cancers begin as polyps, raised lesions in the tissue. Polyps are common in people over age 50, and most
Routine testing for colon cancer can help detect suspicious cells before they start spreading throughout the body.
It’s natural to feel reluctant about signing up for a procedure when you don’t have any symptoms, but detecting colon cancer early
Colon cancer is the
Colon cancer often starts without any symptoms, making early testing for colon cancer an important tool in diagnosis.
There are currently no blood tests for detecting colon cancer.
Stool checks are aimed at detecting blood in your stool, though the presence of blood isn’t a definitive indication of cancer. Benign (noncancerous) polyps can also bleed, as can different medical conditions like hemorrhoids.
Looking for blood in the stool can be a simple way of detecting issues early. Common tests include:
- Guaiac FOBT (gFOBT): Screens for the presence of the hemoglobin component, heme. Some doctors may perform this test as a part of regular health screening after performing a rectal exam.
- Multitargeted stool DNA testing (also known as FIT-DNA): This test can detect hemoglobin as well as altered DNA segments that can be present with cancerous changes.
- Fecal immunochemical (or immunohistochemical) test (iFOBT or FIT): The use of an antibiotic suspension mixed with stool to detect the presence of specific blood proteins.
- At-home tests: Stool test kits available for home use that don’t need to be returned to your doctor or laboratory for results.
An at-home test allows you to get an answer quickly about the presence of blood or other biomarkers in your stool, but you’ll still need to visit the doctor for a follow-up appointment if something is detected.
A sigmoidoscopy is a test performed by your doctor in the clinical setting. You may not need sedation for this procedure, but you may have pre-procedural requirements that ensure the colon is clear of stool for evaluation.
A flexible, lighted viewing tube will be inserted through the anus, into your rectum and into the lower aspect of the colon, the sigmoid colon. The cavity is then filled with air so your doctor can get a clear view of the colon lining.
If any suspicious growths are noted, your doctor can sample or remove them for biopsy at that time.
A virtual colonoscopy is another term for the use of computed tomography (CT) to take noninvasive images of the colon while it’s empty.
Computed tomography uses X-rays to map the lining of your colon. While it can highlight areas of concern, it
If your doctor does see a suspicious polyp, you’ll need a second procedure to remove it.
A colonoscopy is a clinical procedure that’s very similar to a sigmoidoscopy, but with a longer viewing tube that allows your doctor to see the entire colon.
Because the colonoscope must bend around the furthest parts of your colon, some form of sedation is usually used for this procedure.
As with the sigmoidoscopy, your doctor can remove polyps or take samples during this procedure.
The double-contrast barium enema is another noninvasive test.
While not considered a first-line approach to testing for colon cancer, a DCBE uses a contrast substance called barium to help outline variations in the colon’s lining on X-ray.
It may be useful if existing medical conditions prevent you from having other tests.
Your doctor will discuss the pros and cons of each test with you. The best colon cancer test will be determined based on:
- personal preference
- any potential complications
- medical history
- the need for sedation
- follow-up care
- frequency of follow-up testing
- preparation
- cost
Not everyone will be a candidate for every form of testing for colon cancer.
Your doctor will also have an honest discussion with you about your feelings toward colorectal screenings. If you’re adamantly opposed to invasive procedures, starting with a less demanding option is better than not starting at all.
Testing frequency
The U.S. Preventive Services Task Force (USPSTF) recommends testing for colon cancer in most people ages 45 to 49 and for everyone between the ages of 50 and 75.
Testing frequency will depend on your individual needs, but general testing guidelines can span weeks, months, or years.
- Stool tests: every 1 to 3 years
- Sigmoidoscopy: every 5 or 10 years
- Virtual colonoscopy: every 5 years
- Colonoscopy: every 10 years
- Double-barium contrast enema: as recommended
If you have a family history of colon cancer, there’s a good chance genetics are involved.
Lynch syndrome is the
Familial adenomatous polyposis is another inherited condition that can cause cancer in the colon. It’s the result of changes in the APC or MUTYH gene that disrupt normal cell growth, replication, and function.
Genetic testing for colon cancer is performed through a blood sample or saliva test. This can help you know if you live with a specific genetic mutation, but it can’t help diagnose colon cancer.
Testing positive for a colon cancer gene
Testing positive for a colon cancer gene doesn’t mean you’ll develop colon cancer. It does, however, mean your chances of developing colon cancer may be significantly higher than others in your age and health bracket.
Testing for colon cancer is recommended for most people over the age of 45 and everyone between the ages of 50 and 75.
You may not have any symptoms in the early stages of colon cancer. Preventative screening is important for timely treatment, which can significantly improve your cancer survival rate
Your doctor will help you pick the best testing options for your current needs. If you have a strong family history of colon cancer, genetic testing is available.