Overview
- The analysis, published in Annals of Internal Medicine, examined 2003–2017 incidence data for 13 cancers in ages 20–49 versus 50+ across 42 countries using IARC’s GLOBOCAN database.
- Six cancers—leukemia, thyroid, breast, colorectal, kidney, and endometrial—rose in younger adults in at least 75% of countries, and five of these also increased in older adults.
- Colorectal cancer stood out, with incidence rising in under-50s in 88% of countries versus 55% in older adults, and the increases were larger in younger adults in 69% of countries.
- Rates for liver, oral, esophageal, and stomach cancers declined among younger adults in more than half of the countries studied.
- Authors suggest screening in older adults may partly explain the colorectal gap and urge research and prevention guidelines that consider risks across all adult age groups.