Colorectal cancer is now the most common cause of cancer deaths in the US for people under 50
Colorectal cancer – cancer of the large intestine or rectum – is now the leading cause of cancer death among people under 50 in the United States, according to a new study.
The incidence and mortality of colorectal cancer have increased each year in people under the age of 50 since 2013 and 2004, respectively, according to a study published March 2 by the American Cancer Society (ACS). This increase in early diagnoses is due to an advanced stage of the disease. (Colorectal cancer is also known as bowel cancer.)
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Incidence also increases among adults aged 50 to 64 years, with the disease being diagnosed in more advanced stages. This is thought to be related to the similar increase in mortality in this age group, the authors write in the study.
The trend among people under 65 contrasts sharply with the declining rate of new bowel cancer cases and deaths among adults 65 and older. Since most cases are among people 65 and older, this downward trend masks an opposite trend among younger cohorts, the authors write in the study.
A worrying trend
Colorectal cancer is the second cause of cancer death in the world and mainly affects people aged 65 and over. But colorectal cancer “can no longer be called an elderly disease,” Jemal said in a statement. statement. Indeed, a Analysis 2025 found that colorectal cancer cases were simultaneously increasing among people under 50 and stabilizing or decreasing among those aged 50 to 74 in 14 countries, including the United States, Canada, Australia and England.
But in the new study, researchers compiled data on the number of new colorectal cancer cases from 1998 to 2022 as well as the number of colorectal cancer deaths from 1930 to 2023, while focusing on slightly different age cohorts. Data comes from the National Cancer Institute and the Centers for Disease Control and Prevention (CDC).
By narrowing the age ranges examined, the team found that this increase is not only occurring among people under 50, but also among people under 65. “The increase in colorectal cancer is not just among young people per se,” the study authors told Live Science.
This phenomenon is called the “birth cohort effect,” meaning that when an individual was born is more closely related to disease risk than when they were diagnosed. This confirms “a real increase in disease because of something we do or other exposure,” Siegel said in a statement. statement.
However, the cause of this trend remains unclear, the authors write in the study.
“Long-established risk factors for colorectal cancer were identified based on cancer in older adults being exposed to different risk factors than more recent generations,” Siegel, Sandeep Wagle, and Jemal told Live Science. For example, for all ages, nearly 14% of colorectal cancers are attributable to smokingbut people under 50 are less likely than older people to have smoked, they said.
Since the second half of the 20th century, individuals have been exposed to new environmental factors that may increase cancer risk, such as microplastics And ultraprocessed foodsthey said. Research has also shown that colorectal cancer is associated with high exposure to antibiotics and processed meat.
Colorectal cancer screening saves lives
The team estimates that there will be 158,850 new cases of bowel cancer in 2026. Of these, 47,600 will be in people aged 50 to 64 and 24,640 will be in those under 50. More than 55,000 people of all ages are expected to die from the disease this year. Among them, 7% will concern people under 50 and 24% will be people aged 50 to 64.
With most people under the age of 50 diagnosed at an advanced stage of the disease, which is harder to treat, early diagnosis is essential, Siegel, Sandeep Wagle and Jemal told Live Science.
“Earlier diagnosis can also be achieved by increasing awareness of colorectal cancer symptoms like blood in the stool, abdominal pain, diarrhea or fatigue, which can often be confused with other health problems,” they said. “Earlier attention to symptoms could help direct diagnoses toward earlier, more treatable cancer”
Screening also allows earlier detection and removal precancerous lesions in the intestine; which represents 79% of deaths avoided by colorectal cancer. Current ACS Guidelines People at average risk in the state — those without a personal or family history of the disease — should begin colorectal cancer screening starting at age 45. Medicare covers various screening tests from this age, including a stool DNA test and a colonoscopy. There are no specific ACS guidelines for people at high risk, but they may require earlier and more frequent screening.
However, researchers found that only 37% of 45- to 49-year-olds are up to date with their colorectal cancer screenings. With half of deaths in people under 50 occurring between ages 45 and 49, that means many colorectal cancer deaths in this cohort could be avoided, Siegel, Sandeep Wagle and Jemal said.
This article is for informational purposes only and is not intended to offer medical advice.
Siegel, RL, Wagle, NS, Star, J., Kratzer, TB, Smith, RA, & Jemal, A. (2026). Colorectal cancer statistics, 2026. CA: A Cancer Journal for Clinicians76(2), e70067. https://doi.org/10.3322/caac.70067
