Cases of colorectal cancer among young people are rising across the globe, a new study warns.
Research across 36 countries and six continents revealed the disease was becoming more common in people younger than 50 years old.
In the US and the UK, where trends among older adults have stabilized or declined, early on-set rates were rising in younger patients.
South Korea was the worst for younger people, where the number of those diagnosed with colorectal cancer is rising 4.2 percent each year.
The team, from the American Cancer Society, says it hopes the findings lead to an awareness of colorectal cancer among young people and that they recognize the signs so they can get tested before it’s too late.
A new study from the American Cancer Society has found that South Korea had the worst rates of colorectal cancer among young people, rising 4.2 percent each year (file image)
Colorectal cancer is a cancer that starts in the colon or rectum, located at the lower end of the digestive tract.
The cancer usually begins with growths called polyps. They are located on the innermost lining of the colon or rectum and become cancerous over many years.
According to the American Cancer Society, colorectal cancer is the third most common cancer diagnosed in the US, among both men and women.
It is also the third leading cause of cancer deaths in both American men and women and is estimated to cause more than 51,000 deaths in 2019.
For the study, published in the journal Gut, the team looked at rates of colorectal cancer in adults under 50 versus those aged 50 and older.
Of the 36 countries analyzed, colorectal cancer rates in adults under 50 decreased in only three countries: Austria, Italy and Lithuania.
In three countries – Cyprus, the Netherlands, and Norway – colorectal cancer rates in people under age 50 were rising twice as quickly as in people above age 50.
Despite seeing drops in overall numbers, four countries had the starkest contrast between cancer rates in younger and older patients: Australia, Canada, Germany, New Zealand and the US.
In those locations, the falling colorectal cancer rates on the whole were driven by changes in incidence among older patients, but are offset by a surge in younger pateitns.
Meanwhile – in Denmark, Slovenia, Sweden, and the UK – where the numbers are stabilizing, these countries were also seeing an uptick in early-onset cancer.
While the team says it doesn’t know what’s causing the jump, the data shows the uptick started during the 1990s.
A study published in 2017 found that colon cancer cases diagnosed in adults younger than age 55 doubled from 1990 to 2013.
In response to early observations of this trend, the American Cancer Society updated its screening guidelines for colorectal cancer, lowering the age that people at average risk begin regular screenings from 50 to 45.
In Austria and Italy, two of the countries where early-onset is declining, doctors have been screening adults beginning at age 40 and 45, respectively, since the early 1980s.
‘These patterns potentially signal changes in early-age exposures conducive to large bowel carcinogenesis (the initiation of cancer formation),’ said lead investigator Rebeca Siegel, a cancer epidemiologist at the American Cancer Society.
‘Although the absolute risk of colorectal cancer in adults younger than 50 years is low relative to older adults, disease trends in young age groups are a key indicator of recent changes in risk factor exposures and often foreshadow the future cancer burden.’
The authors recommend that doctors record family cancer history and act quickly on symptoms, regardless of patient age.