Posted: March 3, 2017

Colon cancer in young people is on the rise.  A recent article published in the Journal of the National Cancer Institute has created a huge stir.   Click here for the link. In it the authors looked at colorectal cancer incidence in the United States from 1974 to 2013.  What they found was a steady reduction in the incidence of new cases in people over 55 years old, but a sharp increase in incidence in the youngest cohorts examined: 20-29, 30-39 and 40-49.  The spikes have all occurred just since 1990 and the evidence from the data is convincing.   The authors postulate a number of possible reasons, which include primarily life-style alteration with a deterioration in the American diet to one higher in fat, such as seen in fast foods coupled with an explosion of obesity.  They see these changes occurring primarily in younger adults, and the data would tend to support their contention.  Furthermore, they say that the real decrease in incidence in people over 55 is probably a result of increased compliance with screening.  Data from a number of other studies would back up this contention.

Colorectal cancer in young people is still fairly rare, so the significance of these findings is unclear.  Dr. Gilbert Welch, from Dartmouth, a leading cancer epidemiologist, has downplayed their significance in a recent interview because the absolute numbers are so small.  The Affordable Care Act has made it easier for people under 65 to get health care, but this alone cannot explain the increase in cases, because the increase started in 1990.  Colorectal cancer in young people has always been associated with higher mortality, either because of the biologic differences with age or because young people tend not to worry so much about symptoms.  With the potential demise of the ACA one might expect the mortality in people under 65 to increase, as access to health care again becomes an issue.

In any event, these data are sobering.  Whether the US Preventive Task Force will change its screening recommendations based on this single study remains to be seen.