Most cancers not just ‘bad luck’

Although a recent article in the journal Science and a subsequent press release about the article led to a spate of headlines implying that most cancer is due to “bad luck,” David Hunter, Vincent L. Gregory Professor in Cancer Prevention, wrote in a January 15, 2015 Boston Globe op-ed that, in fact, most cancers are preventable.

How do we know that most cancers are not just bad luck?

Cancer rates in populations vary substantially over time within countries and between countries. We know that most of these differences are not due to genetic differences in cancer susceptibility between races. Multiple studies have shown that when people move from a country with a low incidence of cancer to one with high incidence, their offspring acquire the rate of the higher incidence country within a generation or two. So that suggests that it’s the environment and lifestyle within the new country that determines the majority of cancer risk. We usually cannot be completely sure why any individual gets a specific cancer, so there is a chance component, but the international differences show that cancer is mostly due to environment and lifestyle.