Colorectal cancer (cancer that begins in the colon) is the third most common cancer in the United States for both men and women. It often presents no symptoms until the disease progresses, but is highly treatable in its early stages. Regular screenings can identify any abnormalities early on and help to prevent them from turning into cancer.
The exact cause of colon cancer is not fully known, but it occurs when cells in the interior lining of the colon or large intestine grow abnormally and out of control. In most cases, colorectal cancers begin as benign or non-cancerous polyps (small growths that project out from the inside lining of the colon or rectum). Not all polyps turn into cancer, but those that do, typically take several years to do so. Screening for colon cancer is crucial because it allows polyps or abnormal tissue to be detected and removed early, which can prevent cancer from developing. Also, if colorectal cancer is found in early stages, it is extremely treatable.
The American Cancer Society recommends that colorectal cancer screenings should start at age 50 for most people. Earlier screening may be recommended if there is a history of polyps or inflammatory bowel disease or a personal or family history of certain types of cancers.
Types of Colon Cancer Screening
There are several types of colorectal cancer screening tests which include stool-based tests and visual/structural exams:
Fecal occult blood tests
A stool blood test can detect small amounts of blood in your stool that can rarely be seen by the naked eye. A fecal occult blood test (FOBT) or fecal immunochemical test (FIT) is commonly used to detect occult (hidden) blood in a stool, which can be an indicator of an abnormality such as a polyp or cancer. Blood vessels in larger colorectal polyps or cancers are often fragile and easily damaged by the passage of stool, which can cause them to bleed into the colon or rectum. For this test, you receive a kit and instructions for taking a stool sample at home. The kit is then sent to a laboratory for testing. Further investigation is required for a positive test. The benefits of this test are that it is less invasive, easier to have done, doesn’t require any bowel prep, and can be carried out in the privacy of your own home. However, it does need to be done more frequently.
A colonoscopy is used to look at the entire length of the colon and rectum to detect any abnormal areas that may be cancer or polyps. A colonoscope is a thin flexible tube with a light and small video camera on the end. The colonoscope is inserted through the anus and into the rectum and colon. If necessary, special instruments can be passed through the colonoscope to biopsy or remove any suspicious-looking tissue. The test is not painful. Patients are commonly unconscious and relaxed during the test. The benefit of a colonoscopy is that it can be done less frequently than a stool-based test, it can view the entire colon, and it is a very accurate way of detecting and testing abnormalities in their early stages.
A virtual colonoscopy is an advanced type of computed tomography (CT) scan. A CT scan takes a series of images to compose a detailed picture of the interior of the colon and rectum to identify any abnormal areas, such as polyps or cancer. The test involves filling the colon with air and taking CT scans. It is a relatively quick and safe procedure which can typically see the entire colon but is required more often than a regular colonoscopy.
A flexible sigmoidoscopy is similar to a colonoscopy but it does not examine the entire colon. It is used to view the rectum and part of the colon for abnormalities such as cancer or polyps. This type of test is not as widely used as a screening tool for colon cancer, compared to a colonoscopy, as it does not screen the entire colon.
Barium enema testing
The colon can also be viewed with a barium enema with air contrast test, which involves using barium (a chalky substance) and air to fill and expand the colon. X-rays are then taken, which can detect changes or abnormalities in the colon.
Colon Cancer Screening in Central Pennsylvania
At Carlisle Digestive Disease Associates, we’re committed to offering patients comprehensive services and the highest quality of care for their digestive health. If you have concerns about your digestive health or would like to arrange a colon cancer screening, talk to our board-certified gastroenterologists today at (717) 245-2228 or you can request an appointment online.