Cancer is often due to "bad luck" that sees random mutations occur in the cell division process, rather than genetic causes or an unfavorable environment, according to a study by US researchers.
The study released Thursday and published in Science magazine dated January 2, conducted by scientists at Johns Hopkins University, is based on a statistical model taking into account a wide variety of cancers. However, it does not take into account breast cancer, the most common in women or prostate cancer, the second most common in men after skin cancer.
On adult cancers considered, about two-thirds can be explained by random genetic mutations that allow tumors to grow, and one third are the result of genetic factors or an unfavorable environment.
"This study shows that you can increase your risk of cancer by smoking or other bad habits," said one of the authors of this research, Bert Vogelstein, a professor of oncology at the University of Johns Hopkins Medicine.
"Nevertheless, many forms of cancer are largely due to bad luck and a mutation of a gene that cause cancer, without any relation to the lifestyle or hereditary factors," he added.
And, he said, people who live long while smoking or exposure to the sun without special protections without cancer may not have "good genes": "The truth is that most of them just very lucky, "says M. Vogelstein.
For this study, researchers have studied the natural process of cell renewal in the human body. This allows the body to replace cells when they die in different organs.
Researchers have long understood that cancer could arise when stem cells were committing small errors, mutations. But the new study is the first to attempt to understand the proportion of cancers triggered by this process compared to those due to genetics or an unfavorable environment.
"Changing our lifestyle will be very useful to prevent some forms of cancer, but will hardly be effective for other," said Cristian Tomasetti, biomathematician and assistant professor of oncology at Johns Hopkins.
"More resources should be mobilized to find ways to detect these types of random cancers early, treatable," he concludes.
Report of August 2014
13 Comments