Mutations occur each time our cells divide.


Usually, these mutations take place in segments of DNA that aren't very important.


However, if a mutation occurs in a cancer driver gene, we might suffer from some bad luck.


In their paper, Vogelstein and Tomasetti report that 66 percent of mutations are random, 29 percent are caused by environmental factors, and 5 percent are due to hereditary factors.


The JHU team asserts that these mutations aren't the be-all-end-all of cancer - they're just one factor in the process of its development. To that end, other scientists suggest that we must study the interplay of other factors, such as hormones, with genetic mutations to get a better understanding of the whole picture.


While learning that the majority of cancers appear to be unavoidable isn't the most heartwarming news, it does leave us with the knowledge that the other 40 percent are preventable, giving us some control over our health with respect to this awful disease.