If the test provides you zero information about whether it needs treating then it was never a useful test. Presumably it's more like "there's a X% chance this needs treatment". In which case you just set reasonable thresholds for X. E.g. if it's 5% you monitor it, 10% you do a biopsy, 70% you operate, etc.

This is much more sensible than just not testing at all and letting people die from cancer.

> leaving patient scared and anxious during that time

This seems to be the actual motivation. We don't want to scare people with test results so we're just not going to test them. I think that should be up to the patient.