While rates of colon and rectal cancer are dropping for older Americans, they are sharply on the rise for the younger generation, new research published in the Journal of the National Cancer Institute reports.
The study — led by the American Cancer Society (ACS) — looked at cancer data taken from the mid-1980s to 2013. During that time, colon cancer rates rose an average of one to two percent each year for those in their 20’s and 30’s and 0.5 to one percent for those between the ages of 40 and 54.
Rectal cancer rose at an even faster rate. Three in 10 rectal cancer diagnoses are now made in patients younger than 55, and the disease rose about 3 percent per year from 1974 to 2013 in adults aged 20 to 29. But, despite that increase, rates have steadily declined over the past 40 years for those older than 55, Tech Times reports.
In 2013, 10,400 new colorectal cancer cases were found in people in their 40s, and an additional 12,800 cases were diagnosed in individuals in their early 50s. As a result, the team suggests that doctors should reevaluate the age at which cancer screening begins.
“These numbers are similar to the total number of cervical cancers diagnosed, for which we recommend screening for the 95 million women ages 21 to 65 years,” said lead author Rebecca Siegel, a researcher at the American Cancer Society, in a statement.
Though scientists are not sure of the cause behind these trends, the recent drop in colorectal cancer for older people has been attributed to a rise in screening tests able to detect dangerous polyps before they turn into problems. However, such tests have not been used on younger groups. While some less invasive tests are used from time to time, the new research could alter the way researchers look at the disease.
The problem is that colorectal cancer is not easy to diagnose. Unlike other cancers, signs of the disease — diarrhea, constipation, cramping, or abdominal pain — are usually vague or easy to miss.
In addition, scientists are not sure what is driving the rising numbers. Some believe that it could be connected with obesity — which has been linked to both colon and rectal cancer — while others think it may be related to other risk factors, including a sedentary lifestyle, excessive alcohol consumption, and infectious diseases, such as human papillomavirus.
Estimates show that over 95,000 new colon cancer cases and nearly 40,000 new rectal cancer cases will be detected in the U.S. in 2017. Roughly 50,000 are expected to die from the diseases during that time.
“Trends in young people are a bellwether for the future disease burden,” explained Siegel. “Our finding that colorectal cancer risk for millennials has escalated back to the level of those born in the late 1800s is very sobering. Educational campaigns are needed to alert clinicians and the general public about this increase to help reduce delays in diagnosis, which are so prevalent in young people, but also to encourage healthier eating and more active lifestyles to try to reverse this trend.”