Increased incidence of early-onset colorectal cancer driven primarily by white individuals
Incidence of early-onset colorectal cancer has increased in the United States over the past 2 decades, but trends vary considerably by race and ethnicity, according to study results published in Clinical Gastroenterology and Hepatology.
Researchers observed consistent increases in incidence across all younger age groups among white individuals, but smaller increases across most younger age groups among Hispanics. Results showed no change in incidence across any younger age group of Black or Asian individuals.
“Our study presents a comprehensive, up-to-date and age-stratified analysis of early-onset colorectal cancer trends in the United States,” Peter S. Liang, MD, MPH, assistant professor in the departments of medicine and population health at NYU Langone Health, told Healio. “We show that the rise in early-onset colorectal cancer incidence is primarily driven by whites. [This finding] will help guide future research on risk factors for this condition.”
Colorectal cancer is the third most common cancer and second most lethal malignancy in the United States, with an estimated 149,500 new cases and 52,980 deaths expected this year. Approximately 90% of cases are diagnosed among individuals aged 50 years or older. However, incidence has increased among younger individuals, and colorectal cancer is a leading cause of cancer incidence and mortality among those aged younger than 50 years, according to study background.
“Previous studies have examined trends for early-onset colorectal cancer in the U.S., but those data only included 9% to 28% of the population and focused only on Black and white individuals,” Liang said. “We wanted to conduct a more comprehensive and up-to-date study that also included other racial/ethnic groups — specifically Asians/Pacific Islanders and Hispanics.”
Chang and colleagues conducted a nationwide cross-sectional study designed to provide updated analysis of colorectal cancer incidence trends for the entire U.S. population. They used the 2001-2016 U.S. Cancer Statistics database to compare trends by age, race/ethnicity, sex, anatomic site and stage.
Researchers identified 191,659 cases of early-onset colorectal cancer — occurring among individuals aged 20 to 49 years — and 1.10 million cases of late-onset disease, occurring among individuals aged 50 to 74 years.
Results showed colorectal cancer incidence increased during the study period in every age group among individuals aged 20 to 49 years (20 to 29 years, 1.18 cases to 1.38 cases per 100,000 people; 30 to 39 years, 5.52 cases to 6.96 cases per 100,000 people; 40 to 44 years, 14.01 cases to 17.81 cases per 100,000 people; 45 to 49 years, 27.3 cases to 30.84 cases per 100,000 people).
Analyses of late-onset cases showed a slight increase among individuals aged 50 to 54 years (50.68 cases to 57.55 cases per 100,000 people) and decreases in cases among older individuals (55 to 59 years, 80.82 cases to 62.28 cases per 100,000 people; 60 to 64 years, 126.18 cases to 80.24 cases per 100,000 people; 65 to 69 years, 189.12 cases to 106.2 cases per 100,000 people; 70 to 74 years, 247.66 cases to 131.3 cases per 100,000 people).
Whites represented the only racial or ethnic group with a consistent increase in incidence across all younger ages, with the sharpest increase observed after 2012. Among whites aged 45 to 49 years, cases per 100,000 people increased from 25.85 in 2001 to 30.44 in 2016 (average annual percent change, 1.27).
Among Hispanics, researchers observed smaller increases in incidence among individuals aged 20 to 44 years and no change among those aged 45 to 49 years.
The increased incidence among Hispanics aged 20 to 44 years had not been previously reported, Liang said.
“While the increase in incidence is predominantly drive by the White population, we need to be cognizant of the trend among Hispanics, as well,” he told Healio.
Among Black and Asian individuals, researchers found no consistent change in incidence among any younger age group.
Overall, absolute incidence of colorectal cancer remained higher among Black individuals than other racial/ethnic groups. However, the gap in incidence between Black and white individuals appeared to be narrowing among those aged 40 to 49 years, researchers wrote.
The findings may inform future research on risk factors for early-onset colorectal cancer, researchers concluded.
“Given that a number of studies ... have confirmed the rise in early-onset colorectal cancer incidence is predominantly seen in whites, then the risk factors driving this phenomenon should also be disproportionately affecting whites,” Liang said. “We should be thinking about and examining risk factors that fit this profile.”
For more information:
Peter S. Liang, MD, MPH, can be reached at The Liang Lab, VA New York Harbor Health Care System, 423 E. 23rd St., New York, NY 10010; email: firstname.lastname@example.org.