Millennials have double the risk of colon cancer and quadruple the risk of rectal cancer compared with baby boomers, raising serious questions about whether differences in lifestyle or some yet unidentified factor could explain what researchers called a “curious” increase.
While colon cancer has been in sharp decline since 1974 and is still generally concentrated among people older than 50, for adults in their 20s and 30s, rates of the disease increased 1 to 2 percent every year from the mid-1980s through 2013, according to a new analysis of almost 500,000 people, published by researchers at the American Cancer Society.
Rectal cancer rates have increased even faster, rising about 3 percent every year from 1974 to 2013 in adults in their 20s. From the 1980s to 2013, rectal cancer rates for people in their 30s has increased 3 percent every year.
Meanwhile, colorectal cancer rates among older adults are decreasing, thanks in part to successful and widespread screening. In adults 55 and older, colon cancer rates have been falling since the mid-1980s. For rectal cancer, rates have been falling since 1974.
“Trends in young people are a bellwether for the future disease burden,” said lead author Rebecca Siegel, an ACS researcher. “Our finding that colorectal cancer risk for millennials has escalated back to the level of those born in the late 1800s is very sobering.”
Colorectal cancer screening isn’t generally recommended until 50 years old, but some experts are calling for more research to establish different criteria for screening ― or at least raise awareness to let medical professionals and the general public know about this rising risk.
Colorectal cancer is the second-most deadly cancer in the U.S. and the third-most common cancer in men and women. An estimated 95,520 people are diagnosed with colon cancer and 39,910 with rectal cancer every year, according to ACS, and an estimated 50,260 people will die of the cancers in 2017.