Nature

Colon cancer rates are rising in young adults: Is early exposure to a bacterial toxin to blame?

May 1, 2025

Study details: This study analyzed 981 colorectal cancer genomes from 11 countries to explore geographic and age-related differences in mutational processes. The focus was on microsatellite-stable cancers, which comprised 802 of the cases examined.

Results: Significant geographic variations in mutation burdens and signatures were observed among microsatellite-stable colorectal cancers. Notably, mutational signatures SBS88 and ID18, associated with colibactin, were more prevalent in countries with higher colorectal cancer incidence and were 3.3 times more common in early-onset cases (diagnosed before age 40) compared with those diagnosed after age 70. These signatures were also associated with APC driver mutations, with ID18 accounting for approximately 25% of APC driver indels in colibactin-positive cases.

Clinical impact: Findings suggest that early-life exposure to colibactin-producing bacteria may contribute to the increasing incidence of early-onset colorectal cancer. This highlights the potential for targeted prevention strategies and the need for further research into the role of bacterial mutagens in colorectal cancer development.

Source:

Díaz-Gay M, et al. (2025, April 23). Nature. Geographic and age variations in mutational processes in colorectal cancer. https://pubmed.ncbi.nlm.nih.gov/40267983/