Routine screening for colorectal cancer starts at 50 for people at average risk; screening may start earlier for high-risk patients.
The American Cancer Society's Rebecca Siegel, MPH, and colleagues studied data on colorectal cancer cases diagnosed in U.S. adults 20-49 years old in 13 states and cities from 1992 through 2005.
The data show 10,913 new cases of colorectal cancer in men and 9,733 new cases in women during that period.
Overall, the rate of colorectal cancer diagnosis per 100,000 young adults rose by 1.5% per year in men and by 1.6% per year in women.
Hispanic men had a yearly increase of 2.7% per year, compared to 2% for white men and 2.2% for white women. Rates didn't change significantly among other racial or gender groups.
The reasons for the rise in colorectal cancer rates in people younger than 50 isn't clear.