Trends in Early-onset vs Late-onset Colorectal Cancer Incidence by Race/Ethnicity in the United States Cancer Statistics Database

BACKGROUND & AIMS

Colorectal cancer (CRC) incidence has decreased overall in the last several decades, but it has increased among younger adults. Prior studies have characterized this phenomenon in the United States (U.S.) using only a small subset of cases. We describe CRC incidence trends using high-quality data from 92% of the U.S. population, with an emphasis on those younger than 50 years.

METHODS

We obtained 2001 to 2016 data from the U.S. Cancer Statistics database and analyzed CRC incidence for all age groups, with a focus on individuals diagnosed at ages 20 to 49 years (early-onset CRC). We compared incidence trends stratified by age, as well as by race/ethnicity, sex, region, anatomic site, and stage at diagnosis.

RESULTS

We observed 191,659 cases of early-onset and 1,097,765 cases of late-onset CRC during the study period. Overall, CRC incidence increased in every age group from 20 to 54 years. Whites were the only racial group with a consistent increase in incidence across all younger ages, with the steepest rise seen after 2012. Hispanics also experienced smaller increases in incidence in most of the younger age groups. Asians/Pacific Islanders and blacks saw no increase in incidence in any age group in 2016, but blacks continued to have the highest incidence of CRC for every age group. Greater increase in early-onset CRC incidence was observed for males, left-sided tumors, and regional and distant disease.

CONCLUSIONS

Early-onset CRC incidence increased overall from 2001 to 2016, but the trends were markedly different for whites, blacks, Asians/Pacific Islanders, and Hispanics. These results may inform future research on the risk factors underlying early-onset CRC.

A 15-year-old Nepali boy with metastasised colorectal cancer

Nepal suffers from vast inequalities in modern healthcare. The low-income country wrestles with far-reaching insufficiencies in minimal preventative medicine, health awareness, limited infrastructure and difficult topography-all of which contribute to poor access and poor care-seeking behaviour. Our patient came from rural Nepal, where primary healthcare outposts are frequently understaffed and underequipped. He received supportive treatment in his village from the time symptoms presented until he was diagnosed 2 years later, at a tertiary medical centre, with colorectal cancer. An examination of the relevant literature indicates that younger patients often present in later stages of the disease due to initial misdiagnosis or overlooking colorectal cancer as a possibility. Beyond the rarity of the patient's condition, the logistical and financial obstacles he faced in Nepal, particularly outside of the capital of Kathmandu, deterred his access to a higher level of care and delayed his correct diagnosis and treatment.