Authors of a provocative study published Thursday say that their research shows most of the mutations that lead to cancer crop up naturally.
People can get cancer from tobacco smoke or can inherit the trait, but Bert Vogelstein and CristianTomasetti at the Johns Hopkins Kimmel Cancer Center suggest that many cancers are unavoidable, NPR reported.
"We all agree that 40 percent of cancers are preventable," Vogelstein said at a news conference. "The question is, what about the other cancers that aren't known to be preventable?"
Vogelstein, who is also an investigator with the Howard Hughes Medical Institute, explained how he and Tomasetti have refined that question. He said that every time a perfectly normal cell divides, it makes several mistakes when it copies its DNA. These are naturally occurring mutations, NPR reported.
Most of the time, those mutations are in unimportant bits of DNA. That's good luck. "But occasionally they occur in a cancer driver gene. That's bad luck," Vogelstein told NPR.
After two or three of these driver genes get mutated in the same cell, they can transform that healthy cell into a cancer cell.
In their new paper in Science, the researchers attempted to show how often those random errors are an inevitable part of cell division, how often they are caused by variables like tobacco smoke and how often they are inherited.
The researchers found that 66 percent of the total mutations are random, while 29 percent are due to the environment. The remaining 5 percent are due to heredity.
So, what can people do about preventing cancer? "Nothing. Right now, nothing," Vogelstein told NPR.