The Daily Telegraph
Two thirds of cancers are random bad luck
TWO thirds of cancers are unavoidable even if you live a healthy life, a study has shown.
Scientists in the US found cancers are caused by random mistakes in the genetic code that occur when cells divide. The findings challenge the widespread view that such mutations are generally inherited or triggered by environmental factors.
Lead scientist Dr Cristian Tomasetti, of Johns Hopkins Kimmel Cancer Centre in Washington, said: “It is well-known that we must avoid environmental factors such as smoking to decrease our risk of getting cancer.
“But it is not as well-known that each time a normal cell divides and copies its DNA to produce two new cells, it makes multiple mistakes. These mistakes are a potent source of cancer mutations that historically have been scientifically undervalued.”
The research, published in the jour- nal Science, showed that it generally took two or more gene mutations to trigger cancer. In those affecting the prostate, brain and bone, more than 95 per cent were due to DNA errors.
Copying mistakes were linked to 77 per cent of pancreatic cancers but only 35 per cent of lung cancers. Overall, 66 per cent of cancer mutations resulted from copying errors, 29 per cent from lifestyle or environment, and just 5 per cent from inherited genes.