From 2001 to 2021, the number of advanced-stage colorectal cancers in younger adults rose by 2.44% each year, mostly due to tumors in the upper part of the colon, indicating that these cancers are being found later than before, even though colonoscopies are being done more often.

Between 2001 and 2021, colorectal cancer became more common each year in people aged 20 to 44, rising faster than in those aged 45 to 54. The increase was especially steep in cancers located in the upper part of the colon and in cases diagnosed at advanced stages.

Between 1990 and 2021, the number of new cases of colorectal cancer in people under age 45 in the United States rose by 34%, from 32.9 to 43.9 cases per 100,000 people.

From 1990 to 2021, the number of colorectal cancer cases in people aged 40 to 44 rose by 59%, and the rate adjusted for population age increased by 37%, showing that this age group experienced the fastest growth in cases among young adults.

In recent years, more early-stage colorectal cancers in younger adults are being detected, likely due to more frequent screening, but the number of advanced-stage cancers in this group is still rising.

Colorectal cancer is becoming more common and more deadly in people aged 35 to 39, with rates rising by about 1.6% each year. This group, which typically does not undergo routine screening, is seeing the fastest increase in cases and deaths compared to other age groups.