Younger Adults Have Sharpest Increase in Metastatic Colorectal Cancer

A study finds that people aged 20-30 years in the United States had the biggest increase in metastatic, early-onset colorectal cancer between 2000 and 2016, and that Blacks and Hispanics may have the highest risk. 

Cancer is generally a disease of the aging, but doctors are seeing more cases of early-onset colorectal cancer, and the sharpest increase in metastatic, early-onset colorectal cancer is among people 20 to 39 years old, especially Black and Hispanic individuals, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research (AACR).

“We found that proportions of distant-stage colorectal cancer increased over time in most early-onset subgroups with a corresponding decrease in early-stage disease, and that there is a direct correlation between younger age and the likelihood of presenting with distant-stage disease,” said Jordan Karlitz, MD, chief of the Gastrointestinal Division at Denver Health Medical Center and an associate professor at the University of Colorado School of Medicine.

“Although the increasing burden of early-onset colorectal cancer affects all races, these increases seem to be particularly prominent in the youngest non-Hispanic Black and Hispanic subgroups, although absolute case counts remain relatively low,” Dr. Karlitz added. 

Dr. Karlitz and colleagues analyzed data from a national cancer registry for the years 2000-2016, representing 103,975 patients with colorectal adenocarcinoma, the most common form of colorectal cancer. 

They found that the steepest percentage increases in incidence rate occurred for colorectal adenocarcinomas that had spread beyond the colon or rectum and were most pronounced for younger age groups. For metastatic colon adenocarcinoma specifically, the steepest increase in incidence rate occurred among patients 30-39 years old, with a 49 percent increase. For rectal cancer, the greatest increase occurred among 20-29-year-olds (133 percent increase), followed by 30-39-year-olds (97 percent increase) and 40-49-year-olds (48 percent increase). 

In addition to the observed changes in incidence, the researchers also found that younger age was associated with an increased risk for distant-stage colorectal cancer. Patients who were 20-29 years old had a 29 percent likelihood of presenting with distant disease, compared with 20 percent likelihood for 50-54-year-olds.

Looking at race and ethnicity, Dr. Karlitz and colleagues found that the largest increases in distant-stage rectal adenocarcinoma proportions from the 2000-2002 to 2014-2016 time frames occurred among 20-29-year-old non-Hispanic Black individuals (0 percent vs 46 percent), 20-29-year-old Hispanic individuals (28 percent vs. 41 percent) and 30-39-year-old non-Hispanic Black individuals (21 percent vs. 33 percent). For colon adenocarcinoma, distant-stage proportion increased most among 20-29-year-old non-Hispanic Black individuals (20 percent distant-stage in 2000-2002 vs. 34 percent in 2014-2016).  

These findings highlight the importance of identifying individuals at increased risk for early-onset colorectal cancer and optimizing early detection and screening, Dr. Karlitz said, adding that the results support the recent decision to begin average-risk screening at age 45 instead of 50. 

“We hope that the results of our manuscript motivate people to get screened on time at age 45 when they become eligible,” he said. “However, many patients under age 45 will not be eligible for average-risk screening, so it is imperative that we stratify young individuals for early testing based on symptoms and family history,” which, he said, is often overlooked in the care of younger individuals.

“We need to place additional focus on racial subgroups that have an increased tendency to present with distant-stage disease, including the youngest non-Hispanic Black and Hispanic populations, to reverse these trends,” Dr. Karlitz said. Additional research to understand risk factors underlying the rise in early-onset colorectal cancer and later-stage disease is also needed to better understand those who may be at risk, he added.  

A limitation of the study was the use of population-based data from a national registry, which did not include information about the patients’ symptoms or family history.