Dr. Rex answers questions about rising colorectal cancer rates among younger adults
Douglas Rex, M.D., an internationally recognized gastroenterologist, focuses his research on colorectal cancer screening and colonoscopy. We asked him some questions about the rising number of colorectal cancer rates among younger adults.
Traditionally, aging is a risk factor for most cancers and that has included colorectal cancer (cancer of the colon and rectum). The American Cancer Society recommends a baseline colorectal screening at the age of 45. If colonoscopy is used for screening and is negative it should then be performed every 10 years.
Other than age, what are some of the risk factors?
Dr. Rex: Colorectal cancer incidence began to decrease in persons over age 50 in 1985 and the decline accelerated to about 3 percent to 4 percent per year in 2000, coinciding with when Medicare approved screening colonoscopy. The reasons for the increase in persons under age 50 for the past decade are not clear, but may be related to factors such as increasing obesity, changes in gut bacteria, or the introduction of processed foods in the 1970s. In general, risk factors for colorectal cancer include age, positive family history, cigarette smoking, diabetes, obesity and metabolic syndrome.
Are these numbers alarming or a reflection of changing times and changing diets?
Dr. Rex: Regardless of the cause, they are alarming. Since screening (getting checked when you have no symptoms) is not recommended for persons under 45 unless there is positive family history of colon cancer, early attention to symptoms that could mean colon cancer is important for those under 45 years of age.
What are some of the early symptoms of colon cancer?
Dr. Rex: The symptom of greatest importance is rectal bleeding, which may take the form of blood in the toilet bowl or unexplained iron deficiency anemia. Other symptoms such as change in bowel habit and abdominal pain are of less importance, provided they are not accompanied by bleeding.
If you are under the age of 50 and are concerned about your symptoms, what is the best course of action?
Dr. Rex: See your doctor and request an evaluation. Colonoscopy remains the best test.
Have detection methods improved and, if so, which method do you consider the best option for screening younger adults?
Dr. Rex: Screening refers to checking people who have no symptoms, and it’s currently recommended to begin at age 45. The key for those under 45 is to get checked if you have symptoms. If a young person has rectal bleeding with an obvious source on perianal inspection, then anoscopy or flexible sigmoidoscopy, followed by treatment and follow-up in the office until the symptom resolves, may be adequate. If there is painless bleeding and no anal source evident on inspection and digital exam, colonoscopy is the best test.
