Colorectal cancer rates among younger people have almost doubled since 1995, and more people of all ages are being diagnosed with advanced cases of the disease, according to a new study from the American Cancer Society (ACS).

Colorectal cancer is rising among younger adults

According to the report, colorectal cancer is the third most diagnosed cancer in the United States, as well as the third most common cause of cancer-related morality in both men and women. Globally, it is the second leading cause of cancer-related deaths and the leading cause of cancer deaths among men under 50.

For the report, ACS researchers analyzed data from the NCI Surveillance, Epidemiology, and End Results program and CDC's National Program of Cancer Registries from 1995 to 2019. Data on national mortality trends through 2020 were taken from the National Center for Health Statistics.

Overall, the researchers estimated that 153,020 cases of colorectal cancer would be diagnosed in 2023, and 52,550 individuals would die of the disease. Although most cases occur in those 65 and older, the estimates also include 19,550 new cases and 3,750 deaths among people younger than 50.

The overall annual, age-standardized colorectal cancer incidence rate has fallen from a peak of 66.2 cases per 100,000 people in 1985 to 35.7 cases per 100,000 people in 2019. In the early 2000s, colorectal cancer incidence and mortality rates declined between 3% and 4%, but in the last decade, these rates slowed to 1% for incidence and 2% for mortality.

Despite an overall decline in incidence, patients younger than 55 have seen a sharp increase in cases since 1995. The proportion of new colorectal cancer diagnoses was 11% in 1995, but almost doubled to 20% in 2019, even as the number of people in this age group shrunk in the overall population.

Among individuals ages 54 and younger, new colorectal cancer cases grew by 2% annually. Colorectal cancer mortality rates also increased by 1% annually among those younger than 50 and 0.6% annually among those ages 50 to 54.

"We know rates are increasing in young people, but it's alarming to see how rapidly the whole patient population is shifting younger, despite shrinking numbers in the overall population," said Rebecca Siegel, senior scientific director of surveillance research at ACS and the report's lead author.

The proportion of advanced colorectal cancer diagnoses also increased during this period, going from 52% in the mid-2000s to 60% in 2019. Some contributing factors are screening saturation, disproportionate detection and removal of slow-growing adenomas, and earlier onset cancers.

"The trend toward more advanced disease in people of all ages is also surprising and should motivate everyone 45 and older to get screened," Siegel said.

Commentary

According to ACS CEO Karen Knudson, the report's "highly concerning" findings "illustrate the urgent need to invest in targeted cancer research studies dedicated to understanding and preventing early-onset colorectal cancer," and "[t]he shift to diagnosis of more advanced disease also underscores the importance of screening and early detection, which saves lives."

In 2021, the U.S. Preventive Services Task Force (USPSTF) released new guidance that most Americans get screened for colon cancer starting at age 45 instead of age 50. However, Arif Kamal, chief patient officer at ACS, said screening rates for people ages 45 to 55 are still relatively low, even if they have seen some increases in recent years.

Between 2019 and 2021, the proportion of first-time colonoscopies among individuals ages 45 to 49 was 11.6%. In comparison, roughly 7 in 10 people ages 50 to 75 are considered up to date on their colorectal cancer screenings.

The ACS findings "underpin recent guideline changes from the USPSTF and the ACS for adults 45 to 75 years of age to be offered screening for colorectal cancer with one of several modalities," said Michael Shusterman, from NYU Langone's Perlmutter Cancer Center. "Awareness of this change and sensitivity among primary care providers is critical to ensure that screening is provided to all newly eligible individuals."

Overall, health experts say that people ages 45 and older should be regularly screened for colorectal cancer. In addition, all patients, regardless of age, should be aware of potential risk factors, including family history or conditions like irritable bowel disease, and see their doctors about any concerning symptoms.

"It's so important that patients and providers know this is happening,'" said Robin Mendelsohn, co-director of the Center for Young Onset Colorectal and Gastrointestinal Cancers at Memorial Sloan Kettering. "The majority ... will not have cancer, but because we are seeing this increase, it's so important that if you have symptoms, that you be seen by your doctor and that doctors are aware." (Bankhead, MedPage Today, 3/1; Reed, Axios, 3/2; Hou, "Changing America," The Hill, 3/1; Reed, Axios, 3/1; Siegel et al., CA: A Cancer Journal for Clinicians, 3/1)