ISLAMABAD: The majority of cancer cases can be explained by “bad luck” rather than the result of environmental factors and inherited genes, a U.S. study said.
The study, published in the journal Science, found that two-thirds of adult cancer incidence across tissues might be caused by random mutations that occur in dividing healthy stem cells, Xinhua reported.
The findings, based on a statistical model that quantified how much of three factors — bad luck, the environment and heredity — contribute to cancer development, might help researchers design more effective prevention strategies for different cancer types.
“Changing our lifestyle and habits will be a huge help in preventing certain cancers, but this may not be as effective for a variety of others,” said coauthor Cristian Tomasetti, assistant professor of oncology at the Johns Hopkins University School of Medicine and Bloomberg School of Public Health. “We should focus more resources on finding ways to detect such cancers at early, curable stages.”
In the new study, researchers analyzed published data on stem cell divisions in 31 different human tissues and compared the data to the lifetime incidence of cancer in those tissues.
They determined the correlation between the total number of stem cell divisions and cancer risk to be 0.804.
“Our study shows, in general, that a change in the number of stem cell divisions in a tissue type is highly correlated with a change in the incidence of cancer in that same tissue,” said coauthor Bert Vogelstein, professor of oncology at the Johns Hopkins University School of Medicine.
“We found that the types of cancer that had higher risk than predicted by the number of stem cell divisions were precisely the ones you’d expect, including lung cancer, which is linked to smoking; skin cancer, linked to sun exposure; and forms of cancers associated with hereditary syndromes,” said Vogelstein.