As a member of the healthcare community, I've long been taught (as we have all) that test results are only valid in the context of symptoms and at the discretion of a healthcare professional.
That being said, preventative medicine has long suffered at the hands of treatment-based medicine, and at present the cost of routinely conducting tests for the most dangerous of medical conditions is prohibitive for most. In the interest of promoting preventative medicine, what if routine, inexpensive blood tests were used as a prescreening for further condition-specific testing, rather than strictly as an accompaniment to patient complaints of symptoms?
To zero in on one common and dangerous category of conditions in particular, which test results in common blood tests (CBC, CMP, etc.) would most indicate, with high sensitivity and irrespective of symptoms or whether the patient is even experiencing symptoms yet, further testing for potential cancer cases?