As my breast surgeon says, what causes cancer is still a mystery but we are getting a lot better at treating it. With some cancers we can say that the evidence is in, that some activity adds greatly to our risk, like smoking. But recent reports have indicated that possibly a majority of cancers are just bad luck - cells did the wrong thing. We don't fully know, but every month we seem to learn more.
Not much consolation for those who have been diagnosed. But may make a big difference for our kids. In the meantime sticking with our healthy eating, exercise, looking after ourselves regimen is unlikely to do any harm and may do us a lot of good. It's not fair, but cancer isn't a personal attack, on our minds or our bodies. Something went wrong, for whatever reason and we have to do the best we can while we find out more.