Are breast and prostate cancers wildly overdiagnosed? Is it becoming a crass industry rather than honest medical science?

It depends on the country. Overdiagnosis relates to the finding of a cancer that doesn’t act in a life-limiting way. Since the beginning of mammography and PSA eras we have diagnosed a lot of such disease.Mammography has not changed the percentage of women who have metastatic disease, rather it has increased the diagnosis of breast cancer enormously with many, many of these not a threat to life.With respect to PSA screening it’s not clear at all whether it saves lives, either. But such screening increases the number of patients diagnosed and treated for non-disease.But the problem is that up to now we haven’t been able to distinguish disease from non-disease very well so we treat people to be sure. But we’re entering into the era of personalised medicine.
Recently an excellent paper was published showing the size of a breast tumour does not signal malignant behaviour nearly as much as its genetic makeup.