Colorectal Cancer Screenings: What You Need to Know
Colorectal cancer is the third most common cancer in both men and women and the second leading cause of cancer death in men and women combined in the United States. The disease affects more than 4% of both men and women at some time during their life.
While colon and rectal cancers are a reality for many Americans, early detection through screening can and does save lives, which is why the National Comprehensive Cancer Network recommends regular screening for colorectal cancer beginning at age 45. There are multiple colorectal cancer screening strategies your doctor may recommend.
Here, we discuss the different colorectal screening types, how often you should get them, and what to expect during the screening.
What is a colorectal cancer screening?
A colorectal cancer screening is one of a variety of tools to identify the disease before the patient develops symptoms. Using these tests, the doctor may find polyps — a clump of cells that forms on the lining of the colon — before they become cancerous or cancer before it becomes advanced. If the doctor finds polyps or cancer, he or she can remove the affected areas for biopsy.
Symptoms of colorectal cancer do not typically manifest until the cancer is advanced, so the purpose of screening for colorectal cancer is to find lesions before they become symptomatic. If a patient waits for bleeding, pain, change in bowel habits or other symptoms before getting a screening, the tumors are more likely to be advanced and therefore more difficult to treat. Colorectal cancer screening involves testing for colon cancer in patients with no symptoms in hopes of catching smaller, earlier, less-advanced lesions.
When should I begin screening for colorectal cancer?
The U.S. Preventive Services Task Force and the National Comprehensive Cancer Network both recommend those with normal risk factors begin screening at age 50 and continue through age 75. (The American Cancer Society recommends beginning screening at 45.)
However, those with colorectal cancer risk factors should begin screening sooner. This includes:
- A personal history of colorectal cancer or polyps
- A first-degree family history with the disease
- Genetic predispositions to colon cancer (Lynch syndrome or polyposis syndromes)
- Personal history of chronic inflammatory bowel disease (Crohn’s disease, ulcerative colitis)
For those older than 75, you should consult with your doctor to decide whether to continue screening based on your preferences, overall health and screening history.
Types of colon and rectal cancer screenings
While there are several different colorectal cancer screenings, the most important decision you can make is to get screened, regardless of the test you undergo. Screening tests vary by type and frequency, but any abnormal test should be followed with a colonoscopy.
- Highly sensitive fecal immunochemical tests (FIT) and fecal occult blood tests (FOBT) are used to find blood in the stool, which is indicative of polyps or cancer.
- Multitargeted stool DNA tests (mt-sDNA) analyze the DNA from a patient’s stool for abnormal precancerous cells.
- Colonoscopies allow doctors to look inside the entire rectum and colon.
- Flexible sigmoidoscopies (FSIG) allow doctors to check the lower colon and rectum for abnormalities.
- Barium enema exams use x-ray screenings to view the large intestine more clearly.
Colorectal screening frequency
While the frequency of your personal screenings may be dependent on your familial and personal history, most doctors recommend fecal tests annually and more exploratory screenings at regular intervals.
- Highly sensitive fecal immunochemical test (FIT)
- Highly sensitive guaiac-based fecal occult blood test (FOBT)
Every three years
- Multi-targeted stool DNA test
Every five years
- Flexible sigmoidoscopy
- CT colonography
Every ten years
Knowing which colorectal cancer screening is best for you
While organizations like the American Society of Clinical Oncology (ASCO) have developed guidelines to help determine how frequently and which screenings patients should receive, you should speak with your doctor to determine the best colorectal screening regimen for you based on your health, history, preferences and risks.
If you are preparing for a colorectal cancer screening, check with your doctor to confirm you are prepared for the exam. Here’s what you can likely expect:
Highly sensitive fecal immunochemical test (FIT)
- How to prepare — No preparation is necessary for a fecal immunochemical test.
- What to expect — The FIT screening evaluates your stool sample — which may be collected in your own home or primary care office — for blood that is not visible to the naked eye, which may indicate polyps or cancers in your colon or anus.
Highly sensitive guaiac-based fecal occult blood test (gFOBT)
- How to prepare — Your doctor will instruct you on medications to avoid and dietary restrictions to follow in the days leading up to your stool sample collection.
- What to expect — Like the fecal immunochemical test (FIT), the guaiac-based fecal occult blood test looks for hidden blood in your stool sample, which may be collected in the privacy of your home or primary care office.
Multi-targeted stool DNA test
- How to prepare — No preparation is necessary, though you should try to collect a stool sample that is normal for you.
- What to expect — Like the other stool sample tests, the DNA test can usually be completed in your own home or primary care office. The test detects mutations in genes associated with colon cancer, which may be shed in your stool and indicate early signs of colon cancer.
- How to prepare — Before your flexible sigmoidoscopy, you must empty your colon because any residue may obscure your colon or rectum during the exam. Your doctor will give you very specific instructions, which will probably include a special diet the day before your exam, a laxative the evening before your exam, an enema using an over-the-counter kit, and adjustments to your medications.
- What to expect — This exam uses a thin, flexible tube with a video camera (a sigmoidoscope) to view the inside of the rectum and lower colon. During your exam, the doctor will ask you to lie on your side and insert the sigmoidoscope into your rectum. He or she will blow air into your colon to expand the colon and provide a better view of its lining. Because the exam only takes about 15 minutes, unless biopsies are taken, sedation and pain medications typically aren’t necessary.
- How to prepare — Before your CT colonography, you must empty your colon because any residue may obscure your colon or rectum during the exam. Your doctor will give you very specific instructions, which will probably include a special diet the day before your exam, a laxative the evening before your exam, an enema using an over-the-counter kit, and adjustments to your medications.
- What to expect — Also known as a virtual colonoscopy, this screening uses a CT scan to provide hundreds of images of your abdominal organs, which are digitally combined to offer a detailed image of the inside of your colon and rectum. During your exam, the doctor will ask you to lie on your side and place a small tube into your rectum to fill your colon with air, which provides a clearer image. You’ll then lie on your back and be moved into a CT machine, where you’ll be scanned; the doctor will also ask you to turn onto your abdomen for further scanning. The test usually takes 15 minutes.
- How to prepare — Before your colonoscopy, you must empty your colon because any residue may obscure your colon or rectum during the exam. Your doctor will give you very specific instructions, which will probably include a special diet the day before your exam, a laxative the evening before your exam, an enema using an over-the-counter kit, and adjustments to your medications.
- What to expect — A colonoscopy uses a long, flexible tube with a video camera, or colonoscope, to view the entire inside of the colon. You’ll probably be given a sedative and lie on your side, at which point the doctor will insert the colonoscope into your rectum. The doctor will pump air into your colon to inflate it and get a better view of its lining, then he or she will study the entire inside of your colon. They may also insert instruments to take biopsies of any polyps or abnormal tissue they find.
The costs of colorectal cancer screenings
While federal law requires that health insurance plans include coverage of colorectal screenings, they may classify the screenings differently and may not cover costs outside of the test itself. If you are insured, you should review your health plan before scheduling your procedure to gain an understanding of the out-of-pocket expenses you should expect.
If you are not insured, your screening cost will depend on the type of test.
Colorectal cancer screening at AnMed Health
Understanding which colorectal cancer screening is right for you and when is often a complex decision, which is why it’s best to speak with your doctor to establish a schedule for screenings based on your risk factors, age, and preferences. Our physicians at AnMed Health will work with you to decide which of our advanced screenings is best for you and how to protect yourself against colon and rectal cancer.