One of the most common questions that I get, is “what made you go into this field?” usually asked as I am about to insert a scope into a patient’s rectum for his or her screening colonoscopy. The answer is, “it’s a dirty job, but someone has to do it” and “aren’t you glad that I did?” All joking aside, colon cancer is very common in this country. Women often feel that only men get colon cancer, but although men have a slightly higher risk, it is the 2nd most commonly diagnosed cancer in women. 1 in 20 people will develop colon cancer in their lifetime. March is colorectal cancer awareness month, so this is a good time to talk about screening and prevention.
Generally, when patients reach age 50, they receive a birthday gift from their primary care physician or gynecologist — a referral to a gastroenterologist for a colonoscopy. Colon cancer screening starts at age 50 because 90% of these cancers occur over that age. African Americans, and those with a family history of colon cancer in a first degree relative (parents, siblings, children) are at higher risk and should start screening sooner. There are other high risk groups — those with a personal history or family history of certain cancers or medical syndromes — and screening should be individualized for those patients. Screening refers to people who don’t have symptoms. If a patient has symptoms, especially rectal bleeding, change in bowel habits, abdominal pain or unexplained weight loss, he or she should seek medical attention regardless of age or other risk factors.
Colonoscopy is a unique test in that it can both detect and prevent colon cancer. Colon polyps are small growths in the intestine which, if left in place over many years, may grow into colon cancer. A colonoscopy can detect polyps and remove them (prevention), as well as detect colon cancer (screening).
What can a patient expect? She will spend a day on a liquid diet, then take prescribed laxatives to clean out the colon, usually overnight. She goes to an outpatient surgery center and an intravenous line is inserted for sedating medication to be given. While she is asleep, a long thin flexible tube is inserted into the rectum and through the whole colon. We can see the inside of your colon on a video monitor. If polyps are seen, they can be removed, which decreases the risk of colon cancer in the future. If a colon cancer is seen, it can be photographed and biopsies can be taken. When colon cancer is detected through a screening test, before the patient has any symptoms, it is generally curable by surgery. If no polyps or cancer are found, a second colonoscopy is recommended 7-10 years later for low risk patients.
People are reluctant to have a colonoscopy for a variety of reasons. Most have heard about the prep, and are understandably not looking forward to taking the laxatives. There are several different choices now and although patients may find it unpleasant, it is generally not unbearable. There are several risks to the procedure, which we generally discuss in detail at the initial visit. They include rare cases of anesthesia reactions, bleeding and colon perforations.
Alternatives to standard (optical) colonoscopy include virtual colonoscopy, sigmoidoscopy and stool tests to check for blood. Virtual colonoscopy involves taking laxatives, then having a special CT scan of the abdomen to look for colon polyps or tumors. This study has the advantage of being less invasive than a colonoscopy and not needing sedation. It has the disadvantage in that, if a polyp is found, a colonoscopy is needed to remove it. There are also “false positive” tests, which means that something looks like a polyp on the x-rays, but when a colonoscopy is done, nothing is there. There is concern about radiation exposure, as these tests need to be repeated every 5 years. A non-medical concern is that many insurers are not yet paying for the virtual colonoscopy unless there is a compelling medical reason to perform it rather than the standard colonoscopy.
Immunofecal occult blood testing involves putting a bit of stool into a vial for analysis. It is more accurate than the older stool card tests, but not as sensitive as a colonoscopy. If blood is found, a colonoscopy is recommended. If no blood is found, the test is repeated yearly.
Flexible sigmoidoscopy is an office procedure that can be done with a milder laxative preparation. The patient is awake on her left side on an exam table and the scope is inserted through the rectum to 1/4 to 1/3 of the way through the colon. This test has the advantage of not needing sedation, but the disadvantage of not looking at the whole colon. Also, if a polyp is found, a whole colonoscopy is recommended to make sure that no other polyps or tumors are present. I feel that there are 2 significant reasons to discourage female patients from using this as a screening test. One is that women generally have more “twisty” colons in the lower areas than men (due to their anatomy and female organs) or may have had pelvic surgery, leading to more discomfort during the procedure and less accuracy. Second, there is recent evidence that women have a higher incidence of right sided colon cancer (that is beyond the reach of the sigmoidoscope).
Having said all that, ANY screening is better than NO screening for such a common cancer. I always encourage patients who are reluctant to have colonoscopy to consider one of the other methods.
What can you do to prevent colon cancer? There is some suggestion that exercise and a diet high in fruits and vegetables lead to a decreased risk of colon cancer. Smoking, inactivity, obesity and excessive alcohol use have all been shown to increase the risk of colon cancer. In some studies, consumption of large amounts or red meat, charred meats and processed meats has been associated with a higher risk of colon cancer. Therefore, we suggest exercise, maintaining a healthy weight, avoiding cigarettes and limiting alcohol use. A diet rich in fruits and vegetables and low in red meat could be helpful as well.
So, the answer to why I went into this field is that it gives me the opportunity to detect cancer early, to prevent cancer by removing polyps and to make it as pleasant an experience as possible for my patients. (Full disclosure, I am over 50 and have had my screening colonoscopy. Have you?)
For more information on colon cancer screening, check out the Love Your Butt campaign initiiated in memory of a courageous young woman who lost her battle with colon cancer.