International incidence trends in early- and late-onset colorectal cancer: a population-based study

Knowing the global incidence of colorectal cancer (CRC), by sex and age of onset, is of great importance for understanding the disease burden of CRC.

The CRC incidence data, by cancer site, age of onset, sex, country, and year, were retrieved from the Cancer Incidence in Five Continents Vol. Plus database. Estimated annual percentage changes (EAPC) were calculated to quantify the temporal trends in the CRC age-standardized incidence rate.

Globally, the incidence of late-onset CRC was heterogeneous and remained increasing in most countries. The highest incidence of late-onset colon and rectal cancer was both found in males in Slovakia (156.5/100,000 and 121.5/100,000, respectively). The most pronounced increases were mostly observed in developing countries, such as Brazil (colon cancer: EAPC = 5.87, 95% CI 3.18, 8.63; rectal cancer: EAPC = 4.68; 95% CI 2.78, 6.62). The highest incidence of early-onset colon and rectal cancer was found in females in Switzerland (4.2/100,000) and in males in South Korea (4.6/100,000), respectively. The incidences of early-onset CRC were increased in parts of countries, including countries experiencing a decline in late-onset CRC incidence, such as the USA, Germany, and Australia. The temporal trends of colon cancer were mostly aligned with those of rectal in most countries, independent of sex and age of onset.

The increase of early-onset CRC incidence suggests more prevention initiatives are urgently warranted for young adults in the near future. Targeted and effective prevention measures are still needed among elderly populations.