A recent study published in the journal Nature has shed new light on a longstanding mystery in cancer biology: why individuals exposed to identical environmental risks often experience drastically different health outcomes. Many smokers never develop lung cancer, while some lifelong non-smokers do. Likewise, not everyone exposed to sunlight develops skin cancer. The research suggests that inherited genetic backgrounds play a pivotal role in determining which mutations take hold, how tumors develop, and how they might respond to medical treatment.
Duncan Odom, who led the research while at the CRUK Cambridge Institute and is now based at the German Cancer Research Centre (DKFZ) in Heidelberg, Germany, emphasized the significance of the findings. He noted that this is the first time researchers have been able to demonstrate the extent to which a person's genetic makeup influences both the mutation processes and the biological pathways that lead to tumor development. The study utilized four genetically distinct strains of mice to mirror the level of diversity found in human populations. These animals were exposed to identical doses of diethylnitrosamine—a known liver carcinogen found in tobacco smoke and certain processed foods—at 15 days of age under strictly controlled conditions.
By analyzing nearly 600 tumors, the researchers were able to reconstruct how the cancers evolved. They discovered that although many tumours ultimately activated the same biological processes that promote cancer growth, they reached that destination through different mutations and genetic changes, suggesting inherited DNA influences not only cancer risk but also the way the tumour evolves once it begins to form. Sam Godfrey, research information lead at Cancer Research UK, described the study as a fascinating hint that inherited genes exert a major influence on how cancers develop following DNA damage.
The implications of this discovery are significant for the future of cancer screening and precision medicine. Sarah Aitken, an Assistant Professor at the Yale School of Medicine who also worked on the research at the CRUK Cambridge Institute, noted that because genetic background influences both risk and evolutionary trajectory, future prevention strategies must account for inherited genetics and population diversity. Furthermore, the findings suggest that inherited factors could dictate how tumors respond to treatments such as chemotherapy and radiotherapy. Aitken added that since responses to cancer drugs likely differ based on genetics, diagnostics and treatments may need to be tailored accordingly. While researchers caution that more studies are required to understand the full impact on human patients, the findings represent a potential shift in how cancer is understood and how more precise, effective treatments might be developed in the future.
