The epidemiology of colorectal cancer (CRC) is undergoing significant changes, as highlighted by Folasade May, MD, PhD, MPhil, at the 2023 American College of Gastroenterology meeting. Key shifts include:
- Incidence and mortality of CRC are decreasing in those over 65 but increasing in those under 50. Early-onset CRC (EOCRC) now constitutes a larger portion of all CRC cases, a trend observed globally.
- The quick global spread of EOCRC suggests environmental factors, alongside genetic and somatic alterations, may be influencing risk. Notable environmental risks include diet, alcohol and tobacco use, physical activity, and early-life exposures (e.g., maternal obesity, birth by cesarean, breastfeeding, childhood antibiotic exposure).
- An increasing proportion of CRC is occurring in the distal colon and rectum. Links to dietary habits and lifestyle exposures (red meat, alcohol, tobacco) are being explored, along with embryonic origins, infectious agents, inflammation, and microbiome impact on tumor location.