What difference can forty years make? Well, in terms of colorectal cancer, perhaps a 400 percent risk.
New data from study by the American Cancer Society and the National Cancer Institute shows that someone born during the 1990s could have as much as twice the risk for developing colon cancer and four times the risk for developing rectal cancer—at the same age—as a person who was born during the 1950s. Furthermore, since routine screening is typically not advised for most people under the age of 50, by the time doctors find these cancers they are already in more advanced stages.
American Cancer Society epidemiologist Rebecca Siegel explains, “What we found was pretty surprising,” adding that this surge in younger diagnoses is actually in contrast to the overall colorectal cancer trend, which has actually been on the decline for many decades. The lead study author attests, thus, that this decline is most likely a result of older adults benefiting from more consistent regular screenings (which includes colonoscopies) which can identify suspicious growths before they become problematic (read: cancerous).
Siegel also notes that the data—taking into account approximately 50,000 cases of colorectal cancer between 1974 and 2013—did not, however, reveal the reasons for this jump in cases. Indeed, “That’s the billion or trillion dollar question,” comments Dr. George J. Chang, who is the chief of colorectal surgery at MD Anderson Cancer Center. “Boy, it would be great if we knew.”
You would think by now we could know the reasons; after all, Chang made a statistical prediction—using the very same data—that by 2030 approximately 1 in 10 colon cancer cases and 1 in 4 rectal cancer cases will be diagnosed in people under the age of 50; with 50, of course, being the commonly recommended screening age.
Chang comments, “It’s really important to highlight this issue because … young individuals ignore some of the symptoms, and they don’t get worked up.”
On the other hand, Dartmouth Institute for Health Policy and Clinical Practice professor, Dr. H. Gilbert Welch advises the data is still too small to caution it as a trend. After all all, over the last thirty years the annual colorectal cancer rate among people in their 20s has increased at a rate from one to two out of every 200,000 people; but new colorectal cancer diagnoses among people under 50 increased only one in seven per 100,000 people.