Colorectal Cancer Screening OptionsColorectal cancer screening saves lives in two important ways:
- By finding and removing precancerous polyps before they become cancerous
- By detecting the cancer early when it is most treatable
Screening tests for colorectal cancer
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. These are the tests recommended for colorectal cancer screening and some general pros and cons for each:
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 tube with a light and video camera on the end, which allows the doctor to see 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 the pathology lab for analysis. If anything else looks abnormal, a biopsy 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. This test is generally 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 it 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
- 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
Fecal immunochemical testing (FIT)
FIT is a test for hidden blood in the stool. It is a non-invasive, at-home test that detects about 79 percent of colorectal cancers and 30 percent of large colorectal polyps. Because FIT is not as effective as colonoscopy at finding cancer or polyps, it should be done every year. The at-home screening kit is sent to a lab for testing, and people who have a positive result (blood detected) will need to undergo a colonoscopy. FIT has a false positive rate of about 5 percent. The cost of the test is about $25.
FIT-Fecal DNA Test
This test is designed to test 11 different biomarkers found in a stool sample that are associated with colorectal cancer and precancer. The biomarkers include the protein hemoglobin (blood), similar to the FIT and FOBT tests, as well as multiple DNA markers. It is a non-invasive, at-home test that detects 92% of all stage colorectal cancer. After a healthcare provider orders the test, a kit is shipped directly to your home with instructions explaining how to complete the test. After collecting your stool sample, the kit is sent directly to a laboratory for processing and analysis. A positive result requires a follow up colonoscopy. The test should be repeated every three years.
STOOL BLOOD TEST (FECAL OCCULT BLOOD TEST--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 from 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 a vigorous bowel prep
- 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
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)
- Can be uncomfortable
- 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 and it may also miss flat polyps. CT colonography may be best for low-risk patients who cannot undergo or who failed a conventional colonoscopy. 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 or most other insurers as an initial screening test
Colorectal Cancer Screening Tests Covered by Medicare
In 2000, Medicare started paying for colonoscopy for people age 50 and older. Prior to 2000, Medicare only covered the exam for people at high risk or with symptoms. People on Medicare now have more choices for screening tests.
For people on Medicare, this is what is covered:
- Stool blood test (FOBT or FIT) each year for those 50 and over
- Flexible sigmoidoscopy (flex-sig) every four years for those 50 and over at average risk
- Colonoscopy every two years for those at high risk
- Colonoscopy once every 10 years for those 50 and over at average risk
- Barium enema with air contrast instead if a doctor believes that it is as good as or better than flex-sig or colonoscopy
- Virtual colonoscopy is not covered by Medicare as an initial screening test
Colonoscopy is the most commonly utilized screening test for colon cancer since it has a high yield of detecting precancerous polyps and is able to remove them.
The Patient Protection and Affordable Care Act
The Patient Protection and Affordable Care Act, passed in 2010, waives the coinsurance and deductible for many colon cancer screening tests, including colonoscopy, sigmoidoscopy and fecal occult blood testing (FOBT). Colonoscopy is a unique screening test because gastroenterologists are able to remove precancerous polyps during the screening procedure. Under Medicare billing rules, removal of any polyp reclassifies the screening colonoscopy as a therapeutic procedure, for which patients will receive a coinsurance bill. This is often unexpected by patients under the impression that deductible or coinsurance charges were waived.
There are efforts ongoing to correct this problem. ASGE, along with the American Cancer Society Cancer Action Network (ACS CAN), and the American Gastroenterological Association (AGA), are advocating that Congress fix this "cost-sharing" problem, which continues to cause confusion for patients and providers. The Removing Barriers to Colorectal Cancer Screening Act of 2012 introduced in March 2012 by Rep. Charlie Dent, R-PA, waives the coinsurance for a screening colonoscopy regardless of whether a polyp or lesion is found. Congressman Dent's bill applies the same rational policy to beneficiary coinsurance. The expectation is that this will eventually be corrected.
In February 2013, the federal government issued an important clarification on preventive screening benefits under the Affordable Care Act. Patients with private insurance will no longer be liable for cost sharing when a pre-cancerous colon polyp is removed during screening colonoscopy. This ensures colorectal cancer screening is available to privately insured patients at no additional cost, as intended by the new healthcare law. Patients with Medicare coverage must still pay a coinsurance when a polyp is removed as a result of the screening colonoscopy.
Click here for the guidance language provided by the administration. Patients with private insurance should check with their individual providers to learn the details of their coverage and ask about the Affordable Care Act.
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