Prevention is great, but I had read an article last Fall that made a decent argument about how prevention may end up costing a lot more than intervention because often is the case with some diseases, the base rate is soooo low, that if we were to have EVERYONE be screened, etc., then that cost would be more than it would to treat the small number of people who actually end up getting the disease.
I think the more we learn about what the risk factors are (especially biological/genetic, or specific environmental ones), we can get better, more efficient with targeted prevention or intervention with those with subthreshold symptoms.