In an article published on December 17, 2015 by BBC News, journalist James Gallagher reports on a new study suggesting that 70-90% of the risk of developing cancer can be attributed to extrinsic factors. The study was conducted by researchers Song Wu and colleagues from Stony Brook University, U.S., and published in the peer-reviewed journal Nature. The researchers developed four approaches to assess cancer risk: They examined extrinsic risk by tissue cell turnover, reviewed epidemiological evidence, evaluated studies on mutational signatures in cancer, and modeled the potential lifetime intrinsic cancer risk. The results of their multi-method approach indicate that extrinsic factors, such as environmental exposures and behaviors, play a substantial role in the development of cancer. “Cancer is caused by mutations in the DNA of cells, which leads to uncontrolled cell growth instead of orderly growth. But the development of cancer is a complex issue,” stated Yusuf Hanun, director of the Stony Brook University Cancer Center and senior author of the study.
In contrast, a study published in January 2015 in the peer-reviewed journal Science suggests that the majority of the risk of developing cancer is ‘bad luck’, i.e. random mutations during DNA replication in healthy stem cells, and environmental factors or inherited predispositions only play a minor role.
In June 2015, the peer-reviewed journal Carcinogenesis published a series of reviews and a summary paper on the Halifax Project (FPF reported). 174 international scientists assessed the carcinogenic potential of low-dose exposures to chemical mixtures. The scientists concluded that different chemicals can affect various steps of cancer formation, and when present together in a mixture or ‘cocktail’, their combined effects can lead to the malignant disease. Several of the investigated substances are present in food contact materials, like phthalates and bisphenol A.
James Gallagher (December 17, 2015). “Cancer is not just ‘bad luck’ but down to environment, study suggests.” BBC News
Ariana Eunjung Cha (December 17, 2015). “Study: Up to 90 percent of cancers not ‘bad luck,’ but due to lifestyle choices, environment.”
Newswise (December 16, 2015). “Study reveals environment, behavior contribute to some 80 percent of cancers.”
Wu, S. et al. (2015). “Substantial contribution of extrinsic risk factors to cancer development.” Nature (published online December 16, 2015).
Tomasetti, C. & Vogelstein, B. (2015). “Variation in cancer risk among tissues can be explained by the number of stem cell divisions.” Science 347(6217):78-81.
Goodson, W. H. et al. (2015). “Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.” Carcinogenesis, 36(Suppl 1):S254-S296.