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New York, USA: By cutting out environmental and external factors such as smoking, drinking, sun exposure and air pollution, nine in ten cancers could be prevented, new research has found. Following the results of the study, external influences appear to have a far greater impact than previously thought, meaning that many cancers may be more preventable if lifestyle changes are made.
Previous research suggested that random cell mutations played a significant role in the development of tumours, a finding dubbed the ‘bad luck hypothesis’. However, a new study from Stony Brook University in New York suggests that the incidence of cancer is far too high to be explained by simple mutations in cell division.
Although some rare cancers can be driven by genetic mutations, the most prevalent diseases are linked to environmental factors, the study found. According to Dr. Yusuf Hannun, a cancer researcher at Stony Brook University, the new results provide evidence that intrinsic risk factors contribute only modestly to the overall cancer risk, ranging between 10−30 per cent. These figures are supported by previous studies, which have shown how immigrants moving from countries with a low cancer incidence to countries with a high cancer incidence soon develop the same tumour rates, suggesting that the risks are environmental rather than biological or genetic.
Prof. Paul Pharoah, Professor of Cancer Epidemiology at the University of Cambridge, said: “These findings do not have any implications for cancer treatment, but they do tell us that most cancers would be preventable if we knew all of the extrinsic risk factors that cause disease”.
Various studies have shown that some types of cancer are affected by external factors far more than others. In colorectal cancer, for example, 75 per cent of the risk of developing the illness is believed to be linked to diet. Whereas, 86 per cent of the risk of skin cancer is down to sun exposure and 75 per cent of the chance of developing head and neck cancer is due to tobacco and alcohol, research suggests.
Worldwide, an estimated 8.2 million people died from cancer in 2012, according to statistics from Cancer Research UK. More than half of cancer deaths worldwide occurred in countries at a low or medium level of the Human Development Index. Regarding the mortality of different cancer types, lung, liver, stomach and bowel cancer are the most common causes of cancer death worldwide, accounting for nearly half of all cancer deaths.
The study, titled “Substantial contribution of extrinsic risk factors to cancer development”, was published online on 16 December in the Nature journal.
From http://www.dental-tribune.com
