Screening for colon cancer is one of the most important steps you can take to ensure good health. Before colon cancer advances to a life threatening stage, medical tests to detect it are the ONLY way to catch this disease early while it is still highly treatable. Because colon cancer tends to grow slowly, diligent testing makes it more likely cancerous polyps or tumors can be completely removed before they spread. Remember, colon cancer is 90% preventable!
It is estimated that 30% of adults have polyps or benign tumors that may or may not develop into cancer. You should have your first screening at age 50. African Americans, in whom it's been found that colon cancer may develop earlier, should have their first screening at age 45.
Most people do not want to talk about colon cancer or cancer screening. But did you know that every day, thousands of Americans are getting screened including actors and musicians? There is a YouTube video in which CBS anchors Harry Smith and Katie Couric talk about Conquering Colon Cancer. Both have been personally touched by the needlessly tragic disease.
A gastroenterologists is a doctor who specializes in treating the digestive tract as well as performing specific cancer prevention tests such as a colonoscopy or a sigmoidoscopy. Your doctor, including your family practice doctor, discusses similar concerns with dozens of patients every single day so you should not feel embarrassed to discuss your bowel symptoms or testing concerns. It may save your life! Your doctor will help guide you as to when you should be screened for colon cancer and what testing method is best for you.
This is the only test available that allows your doctor to see and examine the entire length of your colon. If a polyp is discovered, it can be biopsied and/or removed during the procedure. Colonoscopies help prevent cancer by removing polyps before they have a chance to become cancerous. This test does not hurt. To help you stay comfortable and relaxed during the test, you will be placed under sedation. A colonoscope, a very small flexible tube with a tiny camera attached, is gently inserted into your large intestine via the annus (rectum). This is done AFTER you are sedated and most patients do not feel or remember it.
The day before your test, you will need to cleanse your intestines (bowels) by following a special diet and using laxatives. Your doctor will provide you with complete instructions and it is very important that you carefully follow them. Cleaning out your system will give the doctor a clear view of the walls of your colon so that any polyps can be detected. Because you will be sedated during the procedure, you will need someone to drive you home after the test is complete. You should plan to take it easy for the remainder of the day. Between the preparation time and the actual test including sedation, you will be using about a day and a half of your time. The test is well worth it and will give you peace of mind. If precancerous polyps were detected, more than likely they were removed during the colonoscopy, preventing cancer from developing.
Computerized Tomography (CT) Colonography or Virtual Colonoscopy
This noninvasive test uses a CT scanner (or in some cases an MRI) to take hundreds of cross-sectional images of your colon. A computer uses these pictures to create an image of your intestines. While you do not have to be sedated, just like with the conventional colonoscopy, you must still cleanse your colon by following a restricted diet and using laxatives before the procedure. Many medical professionals still consider this test experimental and since the patient must cleanse their intestines anyway, (the least pleasant part of the procedure for most patients), they prefer to use the standard colonoscopy since its accuracy in detecting cancer is undisputed.
Using a long slender tube with a camera attached at the end, doctors examine the inner wall of your rectum and lower colon for polyps and growths The tube is gently inserted into the annus and allows doctors to screen about half of the colon. Often performed in a doctor’s office, the test is usually quick with minimal discomfort. The day before the test, you will have to cleanse your intestines by restricting your diet and using over the counter medicines as well as laxatives.
Using barium, a contrast dye, your doctor will evaluate your entire large intestine with an X-ray. Barium is placed in your bowel as an enema and it fills and coats the lining of the bowel providing a clear silhouette of your colon and rectum. Please note that the barium enema has a significantly high rate of missing important lesions. A flexible sigmoidoscopy is often done to aid in detecting small polyps and cancers that the barium enema may miss.
In Home Tests
Fecal Immunochemical Test (FIT)
One of the simplest tests for detecting colon cancer is the relatively new FIT, which looks for hidden blood in the stool. A take-home test that you can use in the privacy of your own home, the FIT is designed to detect blood by reacting to a part of the hemoglobin molecule found in red blood cells. The test is less likely to react to bleeding from other parts of the upper digestive tract. You do not have to follow drug or diet restrictions before taking the test and many patients feel that collecting a sample is easier with the FIT than with the FOBT (described below). This test can be obtained from your primary care physician and it is also usually distributed at clinics. If you would like us to send you a test, please contact one of our Riverside Gastroenterology Specialists.
To use the test at home, you should collect multiple stool samples, following the instructions on the kit. Most often the kit is returned to your doctor or you mail it directly to the lab who will interpret the results. It is recommended that the FIT be conducted annually. If blood is found, your doctor will likely order a colonoscopy to further investigate the source of the blood.
Stool DNA Test
This type of test looks for abnormal sections of DNA (genetic material) that may indicate the presence of cancer. Colorectal cancers and polyps often contain cells with DNA mutations. These cells are shed into the stool where the test may be able to detect them. The DNA test is not invasive and doesn't’ require any preparation but if signs of gene mutations are found, further investigation is warranted and you should have a colonoscopy. The stool DNA test is a relatively new test and more expensive than other stool tests.
Fecal Occult Blood Test (FOBT)
Another take-home test provided by many family practice doctors is the FOBT. Small colon growths or polyps may bleed as fecal matter is passed through the colon. Using a chemical that reacts with your blood, this test looks for hidden blood in the stool. FOBT tests come with instructions on how to collect a small stool sample that you will mail to a lab or return to your doctor’s office for evaluation. If blood is found, your doctor will discuss the need for additional tests with you.