Genetic background determines cancer risk among smokers, study finds

Researchers from Yale Cancer Center, the University of Cambridge and collaborators published a study in Nature showing that inherited genetic differences influence how the body repairs DNA damage caused by smoking and other exposures. In mouse experiments, strains with a susceptible genetic background (C3H) developed liver tumours after a single driver mutation, while more resistant strains (CAROLI) required multiple mutations, delaying tumour onset from an average of 25 weeks to 78 weeks, and sometimes preventing cancer altogether. The work explains why only about 10‑20 % of lifelong smokers develop lung cancer even though roughly 85 % of lung‑cancer deaths are linked to smoking. The authors stress that the findings are based on animal models and that further human research is needed before clinical applications, but they suggest that genetic screening could eventually enable personalised prevention and early‑detection strategies.

The study highlights a universal biological hurdle that may operate in humans, offering a new perspective on cancer risk beyond environmental exposure alone.