Study reveals why DNA damage from smoking and UV rays may cause cancer in some people but not others
New research from the University of Cambridge and the University of Edinburgh provides evidence on why cancer risk varies significantly between individuals exposed to the same environmental triggers. While cigarette smoke and UV radiation are known to damage DNA, this study shows that our inherited genetic makeup dictates how our bodies respond to that damage and how tumors eventually evolve.
Researchers controlled environmental variables by studying mice strains with diverse genetic backgrounds. Every subject received an identical dose of a known carcinogen, allowing the team to isolate the impact of genetics on tumor formation. They analyzed nearly 600 tumors to map how these cancers developed from initial mutations to full-grown tumors.
While cancers across all strains activated the same MAPK signaling pathway, the specific driver mutations acquired were contingent on the inherited genetics of the mouse. Certain genetic backgrounds triggered whole-genome duplication, where the entire set of chromosomes doubles, fundamentally changing the path a tumor takes to develop. This suggests that the biological endpoint of cancer might be the same for many people, but the route taken to get there is pre-determined by an individual's DNA.
The implications for medical practice are significant. Current cancer screening and treatment protocols often assume a uniform response to environmental risks and drugs. This study indicates that future strategies must account for population diversity and inherited traits to improve outcomes. As the medical community moves toward precision medicine, understanding these distinct evolutionary trajectories is a critical step in tailoring diagnostic and treatment plans for patients.
This study reinforces the necessity of considering personal genetic history alongside external risk factors. The findings from this collaboration between institutions in Europe and the United States offer a clearer picture of how cancer starts, moving us closer to more precise methods of intervention.