A recent study from Yale University has brought scientists a step closer to understanding what causes cancer by revealing how much of a tumor’s growth is due to preventable factors, aging, or random chance.
This research, led by Jeffrey Townsend and published in Molecular Biology and Evolution, could eventually help public health experts identify sources of cancer earlier and prevent more cases in the future.
In the United States, many common cancers—like lung cancer and skin cancer—are known to be strongly influenced by lifestyle choices. For instance, smoking is a major cause of lung cancer, and prolonged sun exposure increases the risk of melanoma, a serious form of skin cancer.
But until now, it has been difficult to measure how much any one person’s cancer was caused by preventable behaviors versus factors like aging or genetic luck.
In this study, the Yale team analyzed genetic data from tumors in 24 different types of cancer. They looked at specific patterns of DNA mutations—tiny changes in a person’s genetic code—that can be traced back to known causes like UV light or tobacco smoke.
Each of these causes leaves behind a unique “signature” in the DNA. By examining these signatures, the researchers were able to estimate how much of a tumor’s growth was due to different factors.
The scientists combined this genetic information with a method that calculates how much each mutation contributed to the cancer’s development. This allowed them to go beyond simply identifying the presence of mutations—they could now say how much each one mattered in the actual growth of the tumor.
Their findings show that some cancers are more preventable than others. For example, the majority of mutations leading to bladder cancer and skin cancer could be traced back to environmental exposures—things people might be able to avoid.
In contrast, cancers like prostate cancer and brain tumors (gliomas) were more likely to be caused by internal, age-related processes that are harder to control.
The study also holds promise for communities or professions that experience unusually high cancer rates. These findings could help uncover environmental exposures to cancer-causing substances that may not have been identified before.
If people in a certain area or job are developing the same type of cancer at high rates, scientists could use this method to determine if the cause is likely preventable or not.
While the study represents a major advancement, the researchers also point out that their method doesn’t yet capture every type of genetic change that contributes to cancer. For example, larger changes involving entire genes or chromosomes aren’t fully accounted for yet. More research is needed to understand how these complex changes fit into the bigger picture.
Still, the insights from this study could be valuable for cancer prevention and public health. If experts can clearly identify which cancers are most influenced by external, preventable factors, they can better target education campaigns, improve workplace safety, and reduce exposure to harmful substances—all of which could help lower cancer rates in the long run.
In short, the study moves us closer to answering a long-standing question: how much of cancer is under our control? While not all cancers can be prevented, the findings suggest that many may be avoidable with the right knowledge and action.
If you care about cancer, please read studies that low-carb diet could increase overall cancer risk, and new way to increase the longevity of cancer survivors.
For more information about cancer, please see recent studies about how to fight cancer with these anti-cancer superfoods, and results showing daily vitamin D3 supplementation may reduce cancer death risk.
Copyright © 2025 Knowridge Science Report. All rights reserved.
