Two recent studies have highlighted a disturbing trend that shows the rate of colorectal cancer among people ages 20-50 is on the rise.
Colorectal cancer is the leading cause of cancer-related deaths among non-smokers. One in 20 (5%) Americans will develop colon cancer in their lifetime. Colorectal cancer is generally thought to be a disease that is age-related and typically affects those over the age of 50. This forms the rationale for our screening guidelines that recommend a screening colonoscopy beginning at age 50 for a patient with no family history of colorectal cancer. Since 1975, the rates of developing colorectal cancer have declined among those over the age of 50, a testimony to the success of screening colonoscopy.
Two Eye-Opening Studies
The news is not so good for young adults. In a study published in the Online Journal JAMA Surgery, data was analyzed from nearly 400,000 patients from 1975 to 2010 and showed a nearly 2% increase in the incidence of colorectal cancer for young adults between the ages of 20 and 34 years. The study showed a steady decline in the incidence among those over the age of 50.
Another study reported at the recent American College of Gastroenterology meeting looked at data covering the period of 2000 to 2011. The researchers found that the rate of colorectal cancer among adults of age 20-49 years increased during this period by 1.4% while declining by 3.1% among adults age 50 and older. Disturbingly, it was found that colorectal cancer among young adults tends to present with larger tumors that are more likely to metastasize. Younger adults with colorectal cancer were more likely to be Hispanic or African-American than white.
It is not known why the rate of colorectal cancer is increasing among young adults but it is speculated that obesity, dietary factors, lack of exercise, and genetics play a role. Obesity is a well-recognized risk factor for colorectal cancer and obesity rates among the young are increasing at an alarming rate. Nearly 32% of American youth between the ages of 2-19 years are overweight or obese. The rate among 2-5 year olds is an alarming 23%! In a study looking at colorectal cancer rates among Swedish men, those men who were obese in their youth were 2.37 times more likely to develop colorectal cancer compared to those men who were not overweight during their youth. It is also felt that poor access to high quality healthcare that leads to a delay in diagnosis may be partly responsible for this epidemic among the young. Genetics likely also play a role, although familial syndromes such as Familial Adenomatous Polyposis (FAP) or Lynch Syndrome only accounted for less than 15% of cases. The remaining cases are sporadic meaning that they occur without any obvious genetic risk factor.
What to do?
Currently, our guidelines for colorectal cancer screening do not adequately address screening among adults under the age of 50 unless there is a family history of colorectal cancer. It is generally accepted that screening for colorectal cancer among African-Americans should begin at age 45 regardless of family history. As a practicing gastroenterologist, it makes sense to me to consider a screening colonoscopy at age 40 for thosepatients who have a history of obesity in their youth, especially for Hispanics and African-Americans. I would recommend a colonoscopy for any patient with rectal bleeding that is not obviously explained by external hemorrhoids or an anal fissure or if the bleeding fails to resolve after several weeks of treatment for either of these two conditions. I would also recommend maintaining an ideal body weight through proper dietary habits including eating more than 20 grams of fiber per day (see Dietary Fiber Guide), exercising regularly, and including a dietary supplement that promotes colon health, like The Colon Vitamin, in your daily routine. It can only help with preventing colorectal cancer in your future.
Here’s to your colon health!
Frank Farrell, MD, MPH, AGAF