There is a natural inclination to think that way - but the science doesn't support it. Numerous studies, including a Canadian study of breast cancer over a quarter century, show little if any benefit from early diagnosis. And that doesn't factor in the impact of what is an alarming rate of false positives. 

The 30 percent figure, I suspect, is extremely conservative. We all know people who, though seemingly healthy, spend an inordinate amount of time in the health care system. I think it's partly because it's free and partly because our culture is more preoccupied with disease than health. Women seem especially inclined to engage the medical profession for themselves and their children when the circumstances don't really warrant it.  

I warn them - not completely in jest - that if they keep looking for something wrong, the medical establishment will eventually oblige them.