Long term finasteride is a very confusing issue when it comes to higher grade cancers - which you probably have. It has been shown to be effective in reducing PSA in men with lower grade (Gleason 6) cancers, but NOT in those with higher grades (Gleason 7 or more). This should have been a tip off to your doctor when your PSA remained higher than normal.
My friend just finished Cyberknife at Sloan Kettering. He was having trouble urinating so his doctor put him on finasteride, which really helped. However, once treatment was completed and he had been urinating comfortably for about a month, the doctor immediately stopped the drug because she said that in his case (Gleason4+3) the drug could actually help the cancer grow and since they still don’t know why, they weren’t taking any chances.
So your doctor putting you on this for 3 years - especially without a biopsy - was just plain wrong and in my opinion, irresponsible. Again, I am NOT an oncologist but I do know how to read a study and I do know what my friend’s doctor from a leading cancer institute told him about finasteride.
Listen to all the good advice the guys and Colleen have offered, get yourself in better medical hands, and please tell your doctors the EXACT medicines you are taking. I know you are probably freaking out right now, but you gotta stay calm if you are going to plan the best course of action.
One of the findings in the finasteride study I referenced showed NO INCREASE in mortality for the men (like you) who had higher grade cancers. In other words, your chances of dying from this are the same as the men with the lower grade cancers, which is a big plus! But the treatment you get NOW is the deciding factor in your survival. You CANNOT screw around with anything less than the best care teams out there. Your life depends on it!
Phil