Colorectal Cancer Surpasses Other Cancers in Young Adults
Colorectal cancer has become the leading cause of cancer death among people under 50 in the United States, according to a study in the Journal of the American Medical Association.
Since 2005, colorectal cancer deaths in this age group have risen by 1% annually. This contrasts sharply with the overall decline in cancer deaths among people under 50, which has dropped 44% since 1990. Among the five most common cancers in this age group, colorectal cancer is the only one with increasing deaths.
Rebecca Siegel, senior scientific director of surveillance research at the American Cancer Society, said, “It is absolutely an outlier.”
Rising Cases in Younger Adults
While most colorectal cancer cases still occur in people over 50, diagnoses in those in their 20s, 30s, and 40s have been climbing for decades. Researchers had predicted that colorectal cancer would become the leading cause of death in this group by 2030. The new study shows it reached that milestone seven years early, in 2023.
Siegel and her colleagues analyzed nearly 1.3 million cancer deaths among people under 50 from 1990 through 2023. In 1990, colorectal cancer was the fifth-leading cause of death. By 2023, it had risen to the first.
Other Cancer Deaths Are Declining
Deaths from lung cancer, leukemia, and breast cancer have all declined in this age group. Lung cancer fell from first to fourth, decreasing nearly 6% annually from 2014 to 2023. Leukemia dropped from third to fifth, declining nearly 2.5% per year. Breast cancer remained the second-leading cause of death overall and the leading cause in women, falling 1.4% annually.
Dr. Andrew Chan of Massachusetts General Brigham noted that the decline in other cancers makes the rise in colorectal cancer deaths even more striking. “The rapid increase is remarkable and outpaces declines in other cancers,” he said.
Why Are Deaths Rising?
Rising colorectal cancer deaths can’t be explained by more cases alone. Death rates for other cancers have fallen despite increasing cases, indicating better treatment or early detection.
About 20% of colorectal cancer cases are now diagnosed in people 54 or younger, double the rate in 1995. Experts are unsure why rates are climbing, but several factors may contribute:
- Rising obesity rates and less physical activity
- Changes in gut bacteria
- Diets high in ultraprocessed foods
Siegel noted that these are not the sole causes, and more research is needed.
Screening Is Critical
Given the trend, young adults need to understand their risk and get screened. Symptoms such as blood in stool or stomach cramping should not be ignored.
The U.S. Preventive Services Task Force recommends universal colorectal cancer screening starting at age 45, or earlier for high-risk individuals. “Half of the people diagnosed before age 50 are 45 to 49, so they are eligible for screening,” Siegel said.
