Far from being a marginal phenomenon, the increase in colorectal cancer in young adults today concerns at least twenty-seven countries. According to a study published in the Nature Scientific journal, this increase could be explained by early exposure to a bacterial toxin called Colibactin. Produced by certain strains ofEscherichia coli In the colon and rectum, this molecule would be able to modify DNA in a lasting way.
Scientists at the University of California in San Diego analyzed 981 colorectal cancer genomes from eleven countries, reports the online media Iflscience. Result: changes caused by Colibactin are 3.3 times more frequent in patients under 40 years old than in those over 70 years of age. In a press release, Professor Ludmil Alexandrov, principal author of the study, said: “Its genetic footprint seems to be strongly associated with colorectal cancers in young adults.”
The research team had not initially focused on early cases. Their objective was to understand the differences in colorectal cancer rate between countries. But by studying the data, Marcos Díaz-Gay, researcher at the CNIO (the Spanish Center for Research against Cancer) and the first co-author of the study, says: “One of the most interesting and striking discoveries was the main proportion of changes linked to the Colibactin in the early appearance of cancer.”
An invisible risk from childhood
What is particularly worried about scientists is that Colibactin leads to specific genetic changes from an early age. This alteration could significantly accelerate the appearance of colorectal cancer. Children exposed without knowing it could develop colon cancer at 40 instead of 60, according to Ludmil Alexandrov.
By 2030, colon cancer could become the leading cause of death among young people. Genetic mutations are also more frequent in countries where early cases are numerous. But the precise exposure circumstances of the youngest to this toxin are still vague.
This study was made possible thanks to global collaboration. Samples have been collected in several countries, allowing a large -scale analysis. Without financial support, such discoveries could become rare.
Although many uncertainties remain around Colibactin, the research necessary to remove these gray areas is weakened by budget cuts imposed by the Trump administration. “In my opinion, it will be a blow for cancer research, not only in the United States, but also worldwide”alert Ludmil Alexandrov.
