March is National Colorectal Cancer Awareness Month: Do You Know What Your Screening Options Are?
Prevention through screening for colorectal cancer and removal of precancerous polyps among key factors in saving lives
“The good news is that death rates are declining from colorectal cancer. The bad news is that only about half of those who should be screened are doing so,” said
To learn more about colorectal cancer prevention, log on to the ASGE’s colorectal cancer awareness Web site www.screen4coloncancer.org. Screen4coloncancer.org offers visitors a wealth of vital information including disease facts about colorectal cancer, screening options, what to expect during a colonoscopy, frequently asked questions, the latest news about colorectal cancer such as studies and statistics, links to patient support and advocacy groups, educational videos, and how to find a qualified doctor in your area. The content is available in English, Spanish and Chinese. In addition to these features, is the Peter and Polly Polyp(TM) birthday e-Card encouraging the recipient to get screened for colorectal cancer.
New this year to www.screen4coloncancer.org is a patient education video on colonoscopy. This informative video walks patients through what they need to know before, during and after a colonoscopy.
About Colorectal Cancer
Colorectal cancer is cancer that develops in the colon (large intestine) or the rectum, and usually develops slowly over a period of many years. Before a true cancer develops, it usually begins as a non-cancerous polyp, which may eventually change into cancer. A polyp is a growth of tissue that develops on the lining of the colon or rectum. Certain kinds of polyps, called adenomas, are most likely to become cancerous. The only screening method that allows for the removal of polyps BEFORE cancer develops is colonoscopy.
All men and women over the age of 50 should be routinely screened for colorectal cancer. Colorectal cancer is a preventable and highly treatable cancer when caught at an early stage. Routine screening can save lives. ASGE screening guidelines recommend that, beginning at age 50, men and women with no symptoms who are at average risk for developing colorectal cancer should have a colonoscopy every 10 years. Colorectal cancer is the third most commonly diagnosed cancer and the third leading cause of cancer death in both men and women in
Although colorectal cancer often has no symptoms, warning signs that may indicate colorectal cancer include blood in your stools, narrower than normal stools, unexplained abdominal pain, unexplained change in bowel habits, unexplained anemia, and unexplained weight loss. These symptoms may be caused by other benign diseases such as hemorrhoids, inflammation in the colon or irritable bowel syndrome. However, if you have any of these symptoms, you should be evaluated by your doctor.
To assist the public in understanding the different screening options available, the ASGE has developed a list summarizing recommended screening methods.
Screening is done on individuals who do not necessarily have any signs or symptoms that may indicate cancer. If symptoms exist, then diagnostic workups are done rather than screening.
Stool blood test (fecal occult blood test or FOBT):
This test is used to find small amounts of hidden (occult) blood in the stool. A sample of stool is tested for traces of blood. People having this test will receive a kit with instructions that explain how to take stool samples at home. The kit is then sent to a lab for testing. If the test is positive, further tests will be done to pinpoint the exact cause of the bleeding. A rectal exam in the doctor’s office may examine for occult blood, but this is NOT considered adequate for colorectal cancer screening. The test should only be done with a take-home kit.
A newer kind of stool blood test is known as FIT (fecal immunochemical test). It is like the FOBT, perhaps even easier to do, and it gives fewer false positive results.
- Done at home
- Must be done yearly
- Least effective means of detecting cancer
- Viewed as unsanitary by some
- Patient must retrieve samples of stool in the toilet bowl
- All positive results must be evaluated with a colonoscopy
Flexible sigmoidoscopy (flex-sig):
A sigmoidoscope is a slender, lighted tube about the thickness of a finger. It is placed into the lower part of the colon through the rectum. This allows the physician to look at the inside of the rectum and lower part of the colon for cancer or polyps. This exam only evaluates about one third of the colon. The test is often done without any sedation, so it can be uncomfortable, but it should not be painful. Before the test, you will need to take an enema or other prep to clean out the lower colon.
- Quick — usually a one-to-five minute exam
- Does not require as vigorous a bowel prep as some other methods
- Does not require sedation
- Can only examine the lower third of the colon, the other two-thirds of the colon are not examined
- If polyps are found, the patient must return for a full colonoscopy
Colonoscopy allows for a complete evaluation of the colon and removal of potentially precancerous polyps. It is the only colorectal cancer screening tool that is both diagnostic and therapeutic. A complete bowel cleansing is required before the exam. The procedure uses a colonoscope, a thin, flexible tube with a light and video camera on the end that transmits images to a TV screen that allows the doctor to see inside the entire colon. If a polyp is found, the doctor can remove it immediately. The polyp is usually removed with small biopsy forceps or loop of wire (snare) that is advanced within a channel in the colonoscope. The polyp is then sent to a lab where a doctor called a pathologist looks at it under a microscope for analysis. If anything else looks abnormal, a biopsy (tissue sample) might be done. To do this, biopsy forceps are placed in the colonoscope and a small piece of tissue is removed. The tissue is sent to the lab for evaluation. Colonoscopy is typically done with sedation and is well-tolerated. You will be given medicine that is injected through a vein to make you feel relaxed and sleepy.
- Examines the entire colon, making this the most thorough method for evaluating the colon and rectum
- High detection rate for polyps, including small polyps, and ability to remove them immediately during the procedure
- Typically done with intravenous sedation to assure comfort during the exam
- Given the “Gold Standard” rating above all other screening options by: American Society for Gastrointestinal Endoscopy (ASGE), American Gastroenterological Association (AGA), American College of Gastroenterology (ACG), the American Cancer Society (ACS), and the American College of Obstetricians and Gynecologists (ACOG).
- Requires a complete bowel prep the night before to cleanse the colon
- Unexpected events or complications are rare, but do occur and may include:
- Missing a lesion
- Making a tear in the lining of the colon, which is called perforation
- A bad reaction to the medication used for sedation
Barium enema with air contrast:
A chalky substance, which shows up on X-ray, is given as an enema. Air is then pumped into the colon causing it to expand. This allows X-ray films to take pictures of the colon. Laxatives must be used the night before the exam to clean the colon.
- Done without sedation
- Very low risk
- Uses X-ray radiation
- Can miss larger polyps and growths (over 50 percent polyps 1 cm, and 15 percent of cancers)
- If polyps are found, the patient must be followed up with a colonoscopy
CT COLONOGRAPHY (also referred to as virtual colonoscopy) A small tube is placed in the rectum and air is pumped into the colon to inflate the bowel. Then a special CT scan is used to image the colon. Recent studies show that it is effective in identifying medium to large polyps, but is ineffective in identifying small polyps. CT colonography may be best for low-risk patients who cannot undergo colonoscopy or who have had an incomplete colonoscopy due to various factors. The same bowel prep as conventional colonoscopy is required and it does not use sedation.
- Examines the entire colon
- High detection rate for medium to large polyps
- Low risk
- Air distention of the bowel can be uncomfortable
- Ineffective in detection of small polyps
- Uses X-ray radiation
- If polyps or other abnormalities are found, a colonoscopy must be performed
- Is not covered by Medicare as an initial screening test
- Is not recommended by ASGE screening guidelines or the U.S. Preventive Services Task Force (USPSTF) recommendations
Check with your insurance provider or the Centers for Medicare and Medicaid Services regarding which screening methods are a covered benefit.
The ASGE recommends talking to your doctor about screening options. If you are looking for a qualified physician in your area, please log on to www.screen4coloncancer.com or www.asge.org and click on “Find a Doctor.”
About the American Society for Gastrointestinal Endoscopy
Founded in 1941, the mission of the American Society for Gastrointestinal Endoscopy is to be the leader in advancing patient care and digestive health by promoting excellence in gastrointestinal endoscopy. ASGE, with nearly 11,000 members worldwide, promotes the highest standards for endoscopic training and practice, fosters endoscopic research, recognizes distinguished contributions to endoscopy, and is the foremost resource for endoscopic education. Visit www.asge.org and www.screen4coloncancer.org for more information and to find a qualified doctor in your area.
Endoscopy is performed by specially-trained physicians called endoscopists using the most current technology to diagnose and treat diseases of the gastrointestinal tract. Using flexible, thin tubes called endoscopes, endoscopists are able to access the human digestive tract without incisions via natural orifices. Endoscopes are designed with high-intensity lighting and fitted with precision devices that allow viewing and treatment of the gastrointestinal system.
SOURCE American Society for Gastrointestinal Endoscopy