A new study found that almost two-thirds of cancer types are caused by "bad luck." The findings contradict an earlier belief that all cancers are triggered by poor lifestyle choices and inherited genes.
Researchers at John Hopkins University of Medicine in Baltimore described "bad luck" as the random division of cells in the body that became cancerous by chance.
The team looked at 31 cancer types and found that 22 of them are biologically bad luck, including leukemia and pancreatic, bone, testicular, ovarian and brain cancer. They also identified some cancer types that are hereditary and environmental, such as colorectal cancer, skin cancer known as basal cell carcinoma and smoking-related lung cancer. They did not include prostate and breast tissue analysis in the study.
"When someone gets cancer, immediately people want to know why," Dr. Bert Vogelstein, an oncologist at Johns Hopkins University School of Medicine in Baltimore, said to Reuters.
"They like to believe there's a reason. And the real reason in many cases is not because you didn't behave well or were exposed to some bad environmental influence, it's just because that person was unlucky. It's losing the lottery."
Biomathematician and co-researcher Cristian Tomasetti added that most of the cancer types are simply caused by "randomness."
The findings of the study provided insight as to why some people still get cancer even if they have a healthy lifestyle, and why some treatments are not working for those with cancer. The researchers called for more research that will help detect cancer in its early stage when it is still curable.
"It means screening, it means also new research for new ways to detect cancer earlier," Tomasetti told the Wall Street Journal. "Especially for those cancers where it looks like by far the majority is due to randomness...change in our lifestyle won't affect very much the incidence of that cancer."
This study was published in the Jan. 2 issue of the journal Science.
