Recent research suggested that most cancers arise for intrinsic reasons that cannot be prevented. But a newer study suggests external factors play a vital role – The Guardian
A study published in Science in early 2015 reported that most cancers aren’t preventable and are simply a case of “bad luck”. A year on, however, and a study published in Nature has come to the opposite conclusion: that external factors such as tobacco, sunlight and human papilloma virus play a greater part in whether or not a person gets cancer.
So what does cause cancer: bad luck or avoidable lifestyle choices and environmental factors?
Read the full comment article via the Guardian
Wu, S. et al. Nature: 529,43–47(07 January 2016)
Recent research has highlighted a strong correlation between tissue-specific cancer risk and the lifetime number of tissue-specific stem-cell divisions. Whether such correlation implies a high unavoidable intrinsic cancer risk has become a key public health debate with the dissemination of the ‘bad luck’ hypothesis. Here we provide evidence that intrinsic risk factors contribute only modestly (less than ~10–30% of lifetime risk) to cancer development. First, we demonstrate that the correlation between stem-cell division and cancer risk does not distinguish between the effects of intrinsic and extrinsic factors. We then show that intrinsic risk is better estimated by the lower bound risk controlling for total stem-cell divisions. Finally, we show that the rates of endogenous mutation accumulation by intrinsic processes are not sufficient to account for the observed cancer risks. Collectively, we conclude that cancer risk is heavily influenced by extrinsic factors. These results are important for strategizing cancer prevention, research and public health.
Read the full article here