Colorectal Cancer Screening: What test is right for you?
In the last ten years, the colorectal incidence rate has dropped 30 percent in the United States among adults age 50 and older. While this news is promising, there is still a lot that can be done to help prevent colorectal cancer and detect the disease early, when treatment works best.
Colorectal or colon cancer usually develops when precancerous polyps or abnormal growths develop in the colon or rectum. Left untreated, it is possible for these polyps to turn into cancer. Screening tests are designed to find these polyps, so they can be removed before they become cancerous.
According to the Centers for Disease Control and Prevention (CDC), regular screening – beginning at age 50 – is the key to preventing colorectal cancer. Screening should continue at regular intervals (determined by your doctor) until age 75. Testing may be recommended before age 50 for individuals with:
• A family history of colorectal cancer;
• A diagnosed inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis;
• A genetic syndrome, such as familial adenomatous polyposis (FAP) or Lynch syndrome.
In addition, there are some lifestyle factors that
may contribute to an increased risk for colorectal
• Lack of regular exercise;
• A low-fiber diet lacking in fruits and vegetables;
• Alcohol consumption;
• Tobacco use.
Colorectal cancer does not always cause symptoms, especially during the very early stages of the disease. In fact, it’s not uncommon for someone to have polyps or colorectal cancer without showing any signs, which is why getting a screening test regularly is so important.
Before undergoing any colorectal cancer screening test, you should consult with your doctor to determine the right test for you. There are several different colorectal cancer screening options available, and your doctor will recommend the option he or she thinks is best for you, based on your medical history. A few of the more common screening options are highlighted below.
STOOL DNA TEST
A stool DNA test is designed to detect small amounts of blood and certain abnormalities in genetic material (DNA) from cancer or polyp cells. For this test, a stool sample is collected by the patient using a kit and the sample is mailed to a laboratory for testing. After the test sample has been analyzed, a negative or positive result is produced. Individuals who have a positive finding with this test are advised to undergo a colonoscopy.
Using the sigmoidoscope, your doctor can view the inside of the rectum and part of the colon to detect (and possibly remove) any abnormality. This method allows your doctor to see the entire rectum but less than half of the colon. Your doctor will give you specific instructions to follow on how to empty and clean out your colon and rectum prior to the test, which may include a special diet or the use of enemas or laxatives.
The sigmoidoscopy procedure typically takes about 15 to 20 minutes to complete, and most people do not require sedation. If a small polyp is found during the test, your doctor may remove it and send it to a lab to be analyzed. If the polyp is found to be precancerous, you will be advised to undergo a colonoscopy to look for polyps or cancer in the rest of the colon.
For this test, the doctor uses a colonoscope to view the entire length of the colon and rectum. The colon and rectum must be empty and clean so your doctor can see their inner linings during the test. Your doctor will give you specific instructions on how to prepare for this test, which you should read a few days ahead of time, as you may need to shop for special supplies or pick up a prescription. This preparation method may involve spending lengthy periods of time in the bathroom the day or evening prior to the test, and may prohibit you from eating or drinking anything after midnight the night before your test.
This test does require sedation, which means you will need to arrange for a ride home following the procedure. The colonoscopy test takes about 30 minutes to complete. If a small polyp is found, the doctor will likely remove it during the procedure and send it to a lab for further analysis. Larger polyps, tumors or other abnormalities may require a biopsy to determine if cancer is present.
Talk with your health care provider about what screening option is best for you based on your age and individual risk factors.
Sources: Centers for Disease Control and Prevention (cdc.gov); American Cancer Society (cancer.org); National Cancer Institute (cancer.gov)