Lifestyle and environmental factors might not be the only cause of cancer, a new study suggests. Every new case of cancer depends on a collection of specific mutations in our DNA, and a sweeping new study finds that 66% of the mutations that put us at risk for cancer are the result of unavoidable errors made by cells as they copy themselves millions of times throughout our lives. In other words cancer can strike anybody. This research was published on Thursday in the journal Science, by geneticist Bert Vogelstein and biostatistician Cristian Tomasetti from Johns Hopkins Kimmel Cancer Center at Baltimore, US.
"These copying mistakes are a potent source of cancer mutations that historically have been scientifically undervalued, and this new work provides the first estimate of the fraction of mutations caused by these mistakes", said the paper's lead author Cristian Tomasetti.
All 32 types of cancer were examined by the researchers and it was estimated that 66% of cancer mutations result from copying errors, 29% can be attributed to lifestyle or environmental factors, and the remaining 5% are inherited. They found a strong correlation between cancer incidence and normal cell divisions among 17 cancer types, regardless of the countries' environment or stage of economic development.
This does not undermines the value of lifestyle factors like smoking or exposure to toxic chemicals as they are also very important factors causing nearly a third of cancers. Co-author Bert Vogelstein emphasized that we need to continue to encourage people to avoid environmental agents and lifestyles that increase their risk of developing cancer mutations.
Vogelstein also focuses on two reasons that are of importance the new study:
"We hope this research offers comfort to the literally millions of patients who have developed cancer but have led near perfect lifestyles. Non-smokers who have avoided the sun, these cancer patients eat healthy diets, exercised and done everything to prevent cancer. But they still get it", said Vogelstein.
When it comes to the parent of a child with cancer, they think they either transmitted a bad gene or exposed their child to an environmental agent that caused disease. "This causes a tremendous amount of guilt," said Vogelstein, who is also a pediatrician and has seen such cases.
The second reason the study is important is because cancer will strike about 1.6 million people in the United States this year. "And it will kill 600,000 of us," said Vogelstein. "We need a completely new strategy."
According to Vogelstein it is important to recognize that these enemies exist and hopes new awareness of these random mutations will inspire many scientists to "devote their efforts to various strategies to limit the damage that these internal enemies do".