Colorectal cancer rates are declining in adults 65+, but rising in younger and middle-aged groups.
Many younger adults are diagnosed at later stages, when the disease is harder to treat.
Screening — especially starting at age 45 — remains a critical tool for prevention and early detection.
Colorectal cancer has long been thought of as a disease that primarily affects older adults — but new research suggests that’s changing.
According to the latest data from the American Cancer Society (ACS), rates of colorectal cancer are continuing to decline in people 65 and older, thanks in part to increased screening and prevention efforts.
At the same time, however, diagnoses are rising in younger adults, creating what researchers describe as a concerning split in trends. In fact, colorectal cancer is now a leading cause of cancer-related death among people under 50, and death rates in this group have been increasing slightly each year.
“It's clear that colorectal cancer can no longer be called an old person’s disease,” researcher Ahmedin Jemal, DVM, Ph.D., said in a news release. “We must double down on research to pinpoint what is driving this tsunami of cancer in generations born since 1950.”
How the study was conducted
The findings come from a comprehensive ACS report that analyzes national cancer data over time, tracking both incidence (new cases) and mortality (deaths). Researchers looked at trends across different age groups, allowing them to compare how colorectal cancer patterns have changed for younger versus older populations.
The report also breaks down cases by cancer type and stage at diagnosis. For example, it examines the growing share of rectal cancers and how often cancers are detected early versus at more advanced stages.
By analyzing long-term data, the researchers were able to identify generational patterns — showing that people born after the 1950s are experiencing higher rates of colorectal cancer compared to earlier generations.
What the results show
The results highlight a clear divide. Among adults 65 and older, both colorectal cancer incidence and death rates have been steadily declining — dropping by more than 2% per year in recent years.
In contrast, younger adults are seeing increases. Rates have been rising by about 3% annually among those ages 20 to 49, and nearly half of all new cases now occur in people under 65.
Another key finding: younger patients are more likely to be diagnosed at later stages. About 75% of people under 50 are diagnosed when the cancer has already spread regionally or distantly, which can make treatment more challenging.
The type of cancer is shifting, too. Rectal cancer now makes up about one-third of all colorectal cancer cases — an increase from previous decades.
Researchers emphasize that screening remains one of the most effective tools for prevention. Many cases in younger adults occur in people ages 45 to 49 — the group now eligible for routine screening — highlighting the importance of getting tested on time.