Colon cancer is now the number one cause of cancer deaths in Americans under age 50, taking that position seven years earlier than experts had expected.
This change was reported by researchers in the journal JAMA on January 22. What’s especially concerning is that colon cancer deaths have been rising by about 1% each year since 2005, even though overall cancer deaths in younger people have been falling.
Since 1990, the cancer death rate for people under 50 has dropped by 44%. But among the five most common cancers in this age group, colon cancer was the only one where deaths increased. In 1990, it was the fifth leading cause of cancer deaths for people under 50. By 2023, it had moved to first place.
Other cancers saw large drops in deaths. Lung cancer, for example, dropped from the top spot in 1990 to fourth place in 2023, with death rates falling 6% each year from 2014 to 2023. Leukemia deaths also went down by about 2.5% each year.
Breast cancer is still the second-leading cause of cancer death in younger people, but its death rate is falling too—about 1.4% each year.
Rebecca Siegel, senior scientific director at the American Cancer Society, led the study. Her team reviewed data from nearly 1.3 million Americans under 50 who died from cancer between 1990 and 2023. She described colon cancer as a clear “outlier” because of how its death rate is rising while others are falling.
Experts agree that the increase in colon cancer is not just because more people are being tested. Christine Molmenti, a cancer expert in New York, says the rise in colon cancer deaths is real and not just the result of better screening. In other words, more people are actually getting the disease, and more people are dying from it.
Dr. Andrew Chan, a researcher at Massachusetts General Brigham, added that while we’ve made progress in lowering deaths from other cancers, it makes the increase in colon cancer even more alarming.
One interesting point is that even though more people are getting other types of cancer, the death rates for those cancers are still dropping. This could be because of better treatments that help people survive longer. But colon cancer is not following that trend. The reason for this rise in colon cancer among young adults is still unknown.
Today, about 20% of colon cancer cases are found in people age 54 or younger. That’s twice the rate from 1995. Some possible reasons include obesity, poor diets, not getting enough exercise, and changes in gut bacteria. But doctors believe there may be other causes we don’t yet understand.
Dr. Folasade May from UCLA said the new report feels like a “horror story” for doctors who treat colon cancer. Experts warn that younger people should not ignore warning signs such as blood in the stool or ongoing stomach pain.
Current guidelines say people should start getting screened for colon cancer at age 45. Those with a higher risk may need to start even earlier. Since half of the people diagnosed before age 50 are between 45 and 49, many could benefit from earlier screening.
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The study is published in JAMA.
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