Many types of cancer — including leukemia, pancreatic and brain — are a result of random errors in genetic mutations and are not hereditary or caused by lifestyle, a new study has found.
In an article published Friday in the journal Science, the authors attributed two-thirds of the 31 cancers they studied to “bad luck.”
“Random errors occurring during DNA replication in normal stem cells are a major contributing factor in cancer development,” the authors wrote.
“Only a third of the variation in cancer risk among tissues is attributable to environmental factors or inherited predispositions.”
According to Reuters, the researchers found 22 of the cancers on their list — including leukemia and pancreatic, bone, testicular, ovarian and brain cancer — were largely due to random mutations.
Tissues that underwent more divisions were more prone to tumours.
Hereditary and environmental factors had more of an effect on the other nine — including colorectal, skin and lung cancer.
Gillian Bromfield of the Canadian Cancer Society said, though she hadn’t read the study, other research has found lifestyle can greatly affect the risk of getting cancer.
“Research shows that about half of all cancers can be prevented through healthy living and healthy public policies,” she said in a statement.
“We encourage Canadians to lower their risk of cancer by not smoking, eating well, being active, sitting less, maintaining a healthy body weight, limiting alcohol, being safe in the sun and avoiding indoor tanning.”
But the authors, from Johns Hopkins University, said more resources should be put towards detecting cancer early when it can be cured.
Their results for breast and prostate cancer were unreliable and excluded from the study.