So much for New Year's resolutions. That is the takeaway for many after reading a Johns Hopkins School of Medicine study that concluded that many, if not most, cancers in adults are the result of what the researchers call "bad luck."

Those results are likely to change how we think about the risk of getting cancer — in good ways and bad. While many factors appear to be random, that is no reason to ignore the ways in which behavior can influence the incidence of cancer.

The study by medical statistician Cristian Tomasetti and cancer researcher Bert Vogelstein was largely a statistical exercise. They examined stem cell divisions in different tissues to determine how they correlated with the risk of cancer developing in those tissues. Stem cells are especially important because they constantly divide to repair damaged tissue.