With Cancer, 'Bad Luck' of Random Mutations is Largely to Blame

It turns out that when it comes to cancer, "bad luck" of random mutations plays a predominant role. Scientists have created a statistical model that measures the proportion of cancer incidence, and have found that it's caused mainly by random mutations when stem cells divide.

"All cancers are caused by a combination of bad luck, the environment and heredity, and we've created a model that may help quantify how much of these three factors contribute to cancer development," said Bert Vogelstein, one of the researchers, in a news release. "Cancer-free longevity in people exposed to cancer-causing agents, such as tobacco, is often attributed to their 'good genes,' but the truth is that most of them simply had good luck."

The researchers searched the scientific literature for information on the cumulative total number of divisions of stem cells among 31 tissue types during an average individuals' lifetime. Stem cells "self-renew," which allows them to repopulate cells that die off in a specific organ.

Then, the scientists sorted out the role of random mutations in cancer risk. They charted the number of stem cell divisions in 31 tissues and compared these rates with the lifetime risks of cancer in the same tissues among Americans. This allowed them to determine the correlation between the total number of stem cell divisions and cancer risk to be .804.

"Our study shows, in general, that a change in the number of stem cell divisions in a tissue type is highly correlated with a chance in the incidence of cancer in the same tissue," said Vogelstein. He continues, saying, "This study shows that you can add to your risk of getting cancers by smoking or other poor lifestyle factors. However, many forms of cancer are due largely to the bad luck of acquiring a mutation in a cancer driver gene regardless of lifestyle and heredity factors. The best way to eradicate these cancers will be through early detection, when they are still curable by surgery."

The findings are published in the journal Johns Hopkins Medicine.

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).