[tetramer]

You're right that benefits of screening vary widely depending on type of cancer, type of test, and even a patients own co-morbidities. However, there are a lot of inaccuracies in this comment.

False positives on a screening test are bad because you follow a screening test up with a confirmatory test (a biopsy for cancer) - sometimes the procedure for the biopsy results in additional complications and even death in rare cases (and if it's a false positive, a patient goes through all of that for a benign finding).

I want to be very clear that oncologists are not going to start cancer treatment on the results of a screening test, you need confirmation.