DOCTORS DISCOVER THE TYPE OF COLORECTAL CANCER THAT MOST AFFECTS PEOPLE IN THEIR 40S AND 50S

Young Americans with colorectal cancer are most likely to have the disease in their rectums, experts believe.

A new report from the American Cancer Society provides further evidence for an alarming trend: colorectal cancer (CRC), once seen as a disease of old age, is increasingly affecting people in their 20s, 30s and 40s. 

The ACS predicts in 2026, 158,850 new cases of colorectal cancer will be diagnosed and 55,230 people will die from the disease. 

Despite the disease decreasing by about 2.5 percent per year in people over 65, the report found incidence among adults under 50 - which is considered early-onset - has gone up by about three percent yearly. 

In fact, 45 percent of CRC cancer diagnoses are in people under 65, according to ACS. 

The report found the increase is largely driven by cancers in the rectum and the sigmoid colon, the lowest part of the organ that connects to the rectum. Rectal cancer now accounts for 32 percent of colorectal cancer cases, up from 27 percent in the mid 2000s. 

It's unclear why the rectum and lower colon are primary drivers of the surge, but recent research has honed in on diets that are high in fat but low in fiber, as these contribute to constipation and stool sitting in the lower colon for longer periods of time, allowing bacteria to damage cell DNA.

Processed meats and environmental contaminants such as pesticides also increase exposure to potential carcinogens that end up in stool that sits in the rectum. 

The findings come after another recent study found colorectal cancer is now the leading cause of cancer death in Americans under 50. 

'It's clear that colorectal cancer can be longer be called an old person's disease,' Dr Ahmedin Jemal, senior vice president of Surveillance, Prevention and Health Services Research at the ACS, said.

'We must double down on research to pinpoint what is driving this tsunami of cancer in generations born since 1950.'

The ACS report found colorectal cancer is on the rise among all racial-ethic groups: up two percent for Black Americans; up three percent for Asian Americans, Native Hawaiian and Pacific Islanders, American Indian and Alaska Natives and white Americans; and up four percent in the Hispanic population. 

Overall incidence has increased three percent per year in people ages 20 to 49 and 0.4 percent annually in those ages 50 to 64. 

Rectal cancer specifically in all age groups combined increased by one percent per year from 2018 to 2022. 

The Alaska Native population has the highest colorectal cancer incidence of 81 cases per 100,000 people and 32 deaths per 100,000, twice the rates of the white US population. 

Colorectal cancer is also most often diagnosed in young people at later stages after it has spread to lymph nodes or other organs. 

The report found three in four colorectal cancer patients under 50 are diagnosed at either regional or distant stage, which refers to either stage three or four. 

Within that group, 27 percent are in stage four at the time of diagnosis. 

According to ACS data, the five-year survival rate for localized colorectal cancer is 91 percent, which drops to 74 percent for regional cases. But in distant disease, the survival rate drops to 13 percent. 

Experts believe this is because the signs of colorectal cancer, such as rectal bleeding and abdominal pain, are often mistaken for more benign conditions, especially for young people long thought to not need colorectal cancer screening.

Preventative colonoscopies, the gold standard of colorectal cancer screening, are not recommended in the US until age 45, lowering the chance of the disease being caught early in people who don't yet qualify for screening. 

'Clinicians, health centers, and states have the opportunity to increase the uptake of CRC screening starting at age 45 for those with an average risk of developing the disease,' the ACS experts wrote. 

'People who have a high risk, such as those who have a family history, may be advised to start screening at a younger age.'

The ACS has urged doctors to educate younger patients about lifestyle habits linked to colorectal cancer, including having more than three alcoholic drinks per day, having a body mass index (BMI) of 30 or more, eating high amounts of red or processed meat and low amounts of fiber, lack of physical activity and smoking.

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2026-03-04T19:47:12Z