Cost of false positive is retest and observe, this seems like a very low cost. Also, stop consuming sugar.
1. The cost of a false positive is low. 1a. The cost of a false positive is retesting (what is retesting? Re-mammogramming? Isn't healthcare in USA expensive?) 1b. Observe (so future re-mammogramming and hypervigilance).
2. Additional to the cost of 1a and 1b, cease consuming sugar. Which is a non-insignificant lifestyle change.
What I'm saying is... the statements "Rerun expensive tests and maintain hypervigilance seems like a low cost, in addition to major lifestyle changes that affect every level of one's socioeconomic place (eating out with friends/family, cost of food, food availability, habit breaking, possibly culture clashes, etc)." seems pretty much equivalent to absolute nonsense.
You can be told the risk factors for everybody, but when you are told the risk factors tailored to you it becomes dangerous? Should we tell everyone they're going to live forever so they live in ignorant bliss while healthy?
I can see being unprepared for having that information, but I don't think the solution is not having the information.
There have been studies into exactly this: https://www.ncbi.nlm.nih.gov/pubmed/22859786
Specifically on breast cancer screening, the National Institute for Clinical Evidence in the UK has published management guidance that is quite interesting: https://cks.nice.org.uk/breast-screening
They wouldn't be wold they were positive for cancer. They'd be told that the computer predicts that they are at very high risk for breast cancer. That's knowledge that I think people should have, personally.
I’m not disagreeing that there usefulness to tests, but there is danger too.