My husband turned 50 last week and is now worried about having more risk for colon cancer. How often should a colonoscopy be performed?
ANSWER by Dr. Mark Larson, Gastroenterology, Mayo Clinic of Rochester in Minnesota, United States :
As people get older, the risk for colon cancer also increases. For most people, it is best to start regular screening for colon cancer at age 50 and colonoscopy is one of the recommended screening methods. The frequency with which your husband will require a colonoscopy will depend on the results of the first exam.
Colon cancer is common. According to the National Cancer Institute, more than 140,000 new cases of colon and rectal cancer are diagnosed annually in the United States and of those cases, about 93 percent correspond to people over 50. Actually, age is one of the most important risk factors for colon cancer.
However, there are also other risk factors. Having a family history of colon cancer, especially of a first degree relative of consanguinity (parents or children) diagnosed with the disease, greatly increases the risk. Having chronic inflammation of the colon for several years, as in the case of Crohn’s disease and in ulcerative colitis, also increases the chance of developing colon cancer. Finally, having a personal history of adenomatous polyps (a specific type of polyp in the colon) also increases a person’s chance of developing colon cancer.
Apart from these important risk factors, others can also increase the risk for colon cancer and among them are smoking, moderate to strong alcohol consumption, obesity and sedentary lifestyle.
The American Cancer Society recommends that people who, apart from age, do not have other important risk factors for colon cancer begin screening at age 50. The purpose of detection is to find abnormalities, such as pre-malignant polyps or asymptomatic colon cancer in the early stages. As for the different screening tests, many health care providers recommend their patients to have a colonoscopy, which involves inserting a long, flexible tube (colonoscope) through the rectum and then moving along the entire length of the colon. A tiny video camera placed on the tip of the colonoscope allows the doctor to visualize the inside of the entire colon.
There are also other alternatives for colon cancer detection. One of them is computed tomography (CT) colonography, also known as virtual colonoscopy, which uses CT images to produce a detailed view of the inside of the colon and rectum, regardless of the need to introduce an endoscope through the colon. Another screening alternative is the fecal occult blood test, which consists of a laboratory test that checks the presence of blood in stool samples.
The results of these analyzes determine the frequency necessary for future detections. For example: in the event that no abnormalities are found during the colonoscopy, another follow-up exam may not be required until after 10 years; but in the presence of one or two adenomatous polyps, it would be best to remove them and perform a follow-up or surveillance exam within five years; and if several polyps are found that can be successfully removed, it may be appropriate to shorten the interval between medical follow-ups.
It is very important that your husband start now with colon cancer screenings, because although it rarely shows signs or symptoms in the early stages, when it is detected and treated soon, it is usually curable. In addition, when the screening test discovers polyps in the colon, their removal can decrease the risk of developing cancer.
Everyone, especially people 50 years of age or older, should watch for any possible symptoms of colon cancer. Do not ignore abdominal pain, or colic, or any change in bowel habits, or the presence of blood in the stool, and see a doctor if you experience any of these symptoms.