> Knowing that, do you have to chase down every lump your screening finds? Can you not consider the benefits of investigating further based on the dangers of do

> Knowing that, do you have to chase down every lump your screening finds? Can you not consider the benefits of investigating further based on the dangers of doing so, The problem is this: How do you when to investigate further and when not to? Unless you can come up with a way to make that choice without just rolling dice, you're not really doing any better. > ... the risk factors the patient has, maybe even what you see in successive scans over time? Aside from perverse incentives as mentioned by someone else, there may also be a risk from the scan itself (as in breast cancer screening, e.g.). There's also secondary effects from a positive scan like anxiety before being able to confirm or reject a diagnosis -- this has known health effects. The confirmation itself may have associated risks, etc. It's far from clear that the benefits outweigh the risks[1], so it seems like overkill to call this an indictment of medicine. (I should also add that in e.g. breast cancer women who are known to be at risk -- there's specific genes which carry very high risk (BRCA1, BRCA2) and other genetic factors with high penetrance.) [1] This is also something that many in the medical profession acknowledge, see for example [2] where there's a load of material on breast cancer, specifically. [2] http://sciencebasedmedicine.org/tag/mammography/ http://sciencebasedmedicine.org/tag/mammography/