A large comprehensive research study published in The Lancet Oncology highlights the increasing incidence of early-onset colorectal cancer (CRC) in adults under 50, compared to older adults.
The researchers used data collected from the World Health Organization (WHO)’s International Agency for Research on Cancer database called Cancer Incidence in Five Continents (C15). From C15, researchers extracted data, such as year of diagnosis and sex. The study cut off data in 2017 and looked at five-year increments. The researchers calculated age-standardized incidence rates (ASR) per 100,000 person-years of early-onset (age 25 to 49 years) and late-onset (age 50 to 74 years). The ASR adjusts rates based on the standard population, allowing for comparisons between different time periods and regions. In addition, the researchers estimated average annual percentage changes (AAPC) to assess how incidence rates changed over time.
The study found that the highest incidence rate of early-onset CRC (EO-CRC) occurred in Australia (ASR 16.5), the United States territory of Puerto Rico (ASR 15.2), New Zealand (ASR 14.8), the United States (ASR 14.8), and South Korea (ASR 14.3). Uganda (ASR 4.4) and India (ASR 3.5) had the lowest incidence of EO-CRC.
When looking at late-onset CRC (LO-CRC), the highest incidence occurred in the Netherlands (ASR 168.4) and Denmark (ASR 158.3). Interestingly, similar to EO-CRC findings, LO-CRC rates appeared lowest in Uganda (ASR 45.9) and India (23.5). When examining the AAPC for the most recent ten years, the data revealed that incidence rates of EO-CRC remained stable in 23 (46%) countries/territories and increased in 27 (54%) countries. New Zealand (AAPC 3.97%), Chile (AAPC 3.96%), Puerto Rico (AAPC 3.81%), and England (AAPC 3.59%) had the most significant increases in AAPC. In 14 of the 27 countries/territories with increasing EO-CRC, AAPC regarding LO-CRC remained stable or decreased.
Notably, 13 countries/territories had increasing AAPC in both EO-CRC and LO-CRC. AAPC increased more in younger versus older adults in 6 countries (Chile, Japan, Sweden, the Netherlands, Croatia, and Finland). AAPC increased more in older versus younger adults in four countries/territories (Thailand, France [Martinique], Denmark, and Costa Rica. AAPC remained similar between EO-CRC and LO-CRC in Türkiye, Ecuador, and Belarus.
The study also revealed that the rise in EO-CRC occurred faster in men than women in several countries, including Chile, Puerto Rico, Argentina, Ecuador, Thailand, Sweden, Israel, and Croatia. Women in England, Norway, Australia, Türkiye, Costa Rica, and Scotland experienced a faster rise in EO-CRC than men.
The authors stress the need for new, concerted efforts to raise awareness of CRC screening and promote early detection in young adults, as rising rates of EO-CRC were found in 27 of the 50 countries/territories included in the study.
Source: Lancer Oncol
