An enlarged prostate causes elevated PSA readings: the larger a prostate is, the more PSA is produced, so prostate size should be taken into account for PSA readings to be meaningful.
Another suggestion is to have a "freePSA" test which gives the % of PSA being produced normally and will indicate the probality of cancer.
Unfortunately there are a lot of grey areas with PC, and biopsies can sometimes not detect a cancer if, for example, the cancer is small, or only a few samples were taken.
Given all of your information, you need to be more proactive, and consult a medical oncologist expert in PC.
Post Edited (aus) : 4/24/2009 5:26:30 AM (GMT-6)