From 2001 to 2020, early-onset colorectal cancer was most common in the southern U.S., but its numbers grew slowly there; in the western U.S., it started less common but increased faster, showing different patterns of growth between the two regions.

Between 2001 and 2020, the number of new cases of colorectal cancer in adults aged 20 to 54 rose in every region of the United States, with the fastest increase in the West and the slowest in the South, showing that different areas experienced different rates of growth in this disease.

In the United States, the number of people under age 50 diagnosed with colorectal cancer has risen significantly since the 1990s, from about 8.6 to 12.9 cases per 100,000 people.

In the United States, the number of colorectal cancer cases in people under 50 increased by 49% between 1990 and 2021, from about 6,256 to 9,311 cases, indicating a growing trend in this age group.

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 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.