A better understanding of the role of the identified and avoidable causes of the disease and those linked to aging or chance makes it possible to advance on all the factors that trigger the cancer mechanism.
- DNA changes cause tumors to appear or grow
- These mutations may be due to identified and preventable factors
- But aging and chance also play a role in the appearance and evolution of cancer.
“What turns cells into cancer instead of remaining normal tissue?”. It is THE question around which revolves the debate on the possibility of having control over the appearance and development of this disease. And it is the one posed by Yale researchers in order to be able to quantify the factors causing DNA modifications that contribute to the appearance of cancer and the growth of tumours. “We can now answer the question: what is the underlying source of cancer-causing mutations?“, explains Professor Jeffrey Townsend in the article in the journal Molecular Biology and Evolution which reports on the work it has piloted.
If this question of the true origin of cancer is central, it is because we now know that most of these diseases are preventable by simple lifestyle choices. Protecting yourself from exposure to the sun helps to avoid melanoma, not smoking to avoid developing lung cancer. So much for two diseases linked in a caricatural way to behaviors. Yes, but… Not all those who receive ultraviolet rays have skin cancer, not all smokers develop lung tumours. So what is the role of behaviors in the onset of the disease compared to two other factors, aging and… luck?
The share of known or unknown factors
Since it is possible to reliably predict cancer-causing mutations that are linked to known risk factors, Jeffrey Townsend’s team sought to establish the specific percentage of these factors and that of other unknown factors such as aging or chance. “This gives us the final piece of the puzzle to connect what happened to our genome with cancer: we look into the tumor and see there the signal of what caused the cancer.“, explains the scientist.
And this is how I was able to establish that while bladder tumors yes of the skin are very often linked to preventable factors, prostate cancers or gliomas are more often attributable to internal processes age related. “This can be useful to give people feedback that allows them to know what the causes of their cancer are… Not everyone necessarily wants to know, but for some it is important to be able to attribute cancer to its cause.“, emphasizes Jeffrey Townsend.
Discover new causes
The work carried out could also make it possible, by analyzing cases of cancer in populations suffering from abnormally high levels of the disease, to discover exposures to carcinogenic substances hitherto ignored. Even help public health officials put in place preventive measures against newly identified sources of cancer. But the Yale researchers recognize a limit to their work: “Not all genetic changes that lead to tumors are incorporated into the current approach and more research will be needed to understand complex genetic changes like duplicate genes or chromosomes.“, admits the Mr Townsend
