Colorectal Cancer’s Shift Toward Younger Adults

Last month, the American Cancer Society released its triennial Colorectal Cancer Statistics 2026 report. This report offers readers a look at evolving trends in incidence, mortality and patient demographics in colorectal cancer across the United States. Notably, the findings from this report show that colorectal cancer is increasingly affecting younger populations.

Incidence rates are rising among adults under 65, with the sharpest increases observed in those aged 20 to 49, and nearly half of all new diagnoses now occurring in individuals younger than 65. Younger patients continue to be diagnosed with advanced-stage disease, highlighting persistent gaps in early detection.

To further explore these trends and what they mean for patients, CURE sat down with Rebecca L. Siegel, MPH, senior scientific director of Cancer Surveillance Research at the American Cancer Society. In the interview, she discusses the key takeaways from the report.

CURE: The 2026 Colorectal Cancer Statistics report highlights a concerning rise in colorectal and rectal cancer among younger adults. What are the most important takeaways patients should understand from these findings?

Siegel: Colorectal cancer incidence and mortality are rising among younger generations (born after the 1950s). Many colorectal cancer deaths in people under age 50 could be prevented because half are in people aged 45 to 49 years who are eligible for screening. In addition, three in four colorectal cancers among people under 50 are diagnosed at advanced stages, when the disease is harder to treat.

Unfortunately, most cancers do not cause symptoms until they are more advanced, which is why screening is so important beginning at age 45 for average-risk adults (earlier with higher risk). Earlier diagnosis can also be achieved by increasing awareness of symptoms for colorectal cancer, like blood in stool, abdominal pain, diarrhea or fatigue, which can often be mistaken for other health issues. Earlier attention to symptoms could help shift diagnoses toward earlier, more treatable cancer.

The data show that nearly half of new colorectal cancer cases now occur in individuals under 65. What factors may be contributing to this shift toward younger populations?

A few studies have shown a likely contribution from increased excess body weight and sedentary activity (e.g., more screen time and less physical activity), which are established risk factors for colorectal cancer. However, reasons for increasing risk are not well understood. Established risk factors are based on cancer in older adults who had different exposures than those in more recent generations.

For example, 14% of colorectal cancer in all ages combined is attributable to smoking, but that percentage would be much lower in people younger than 50 years, who are much less likely to smoke. Newer exposures since the early 20th century, such as dietary changes like ultra-processed food, antibiotics and microplastics are under still investigation regarding their association with colorectal cancer.

Screening is recommended starting at age 45, yet uptake remains relatively low. What barriers are preventing eligible individuals from getting screened?

In 2023, only 37% of people aged 45 to 49 were up to date on their colorectal cancer screening, but this number is only 14% for people without insurance. One of the largest barriers for screening is lack of access to care, which is why insurance subsidies are so important. Screening is about 40% among people with insurance, regardless of whether it is private or through Medicaid or other public sources.

Many adults are unaware that screening now starts at age 45 and discomfort, fear or misconceptions about screening tests, especially colonoscopy, continue to prevent some people from participating. Importantly, stool testing is a recommended screening option because it reduces mortality from colorectal cancer the same as colonoscopy as long as it’s done regularly and an abnormal test is followed up with colonoscopy. It is a preferred option for many younger adults and people of color because it’s done in the privacy of your home at your convenience and is a lower cost option.

For patients in their 20s, 30s and 40s, what symptoms should not be ignored, even if they seem minor?

Symptoms like blood in stool, abdominal pain, diarrhea or fatigue can often be mistaken for other health issues, especially among younger people. It is important to pay attention to one’s bowel movements and talk to your provider immediately if changes are observed. Increasing awareness among both people and their healthcare providers is critical to ensure timely evaluation.

The report highlights disparities, particularly among Alaska Native and American Indian populations. What steps are needed to address these inequities in outcomes?

American Indian and Alaska Native people have the highest colorectal cancer incidence and mortality in the U.S., and Alaska Native people have the highest rates in the world for reasons that are not well understood. A major obstacle in reducing the burden in Alaska Native people is barriers to research funding because the population is small. Addressing disparities among Alaska Native and American people requires both improving access to care and sustaining culturally tailored interventions.

The high colorectal cancer burden among Alaska Native people may relate in part to limited access to endoscopic services across much of Alaska, although targeted initiatives within the Alaska Tribal Health System have increased screening uptake in recent years.

What progress is being made in understanding the underlying causes of early-onset colorectal cancer?

There have been a handful of studies published, but etiologic research requires substantial funding and time, and research funding is currently under threat.

In light of last month being Colorectal Cancer Awareness Month, what is the importance of this initiative and others like it?

The importance of this study is to understand and increase awareness of the rising incidence of colorectal cancer. Cancer cannot be controlled if we do not understand what our risk is and how it is changing. None of this information would be known without cancer registries, which is why they are so important for public health.

The importance is to increase awareness of the urgent need for research to discover the cause of rising incidence and to increase awareness of symptoms and de-stigmatize the disease to facilitate earlier diagnosis; the 5-year survival rate for early-stage colorectal cancer in people under 50 years is 95%.

Screening can also save lives by preventing the disease as well as detecting it early.

References

1. "Colorectal cancer statistics, 2026," by Dr. Rebecca L. Siegel, et al. CA: A Cancer Journal for Clinicians.

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