PCA-3 question

Almost all of the literature about PCA-3 says it is only useful in a situation where an initial biopsy was negative. I don't understand the science behind that reasoning. Either the test is accurate enough to be worthwhile or it isn't. If it is worthwhile, a low PCA-3 score at any time would seem to be very meaningful. If a doctor recommends an initial biopsy because PSA is rising, and the result is negative but those conditions persist or worsen, a second biopsy may be recommended. But if the PCA-3 score is low that may be reason to delay the 2nd biopsy for a while. Why? If the PCA-3 was taken before the initial biopsy and it was low then why was that data point ignored then but not for the 2nd biopsy?

Beware... Every insurance company that I investigated will NOT pay for the PCA3 test. I spent months fighting my insurance company who refused to pay the $600 lab bill. I strongly advise anyone whose Uro orders a PCA3 tests to insist that the doctor get pre-authorization from the insurance company.

-Gedman