In reply to Trangia:
Just to balance this thread a little, PSA is a poor test, neither very specific (ie if the test is negative that you don't actually have it) or sensitive (ie if it is positive that you actually have the disease.)
2 big studies to sort out whether screening with PSA works completely failed to settle it, one said no, one yes, but neither were perfectly designed, and the one that said yes had a calculated cost of $5mill US to save one cancer death (health economics of screening is a whole other argument.)
The problem is that it is best to consider prostate ca like 2 seperate conditions: a faster aggressive disease that can kill you, and a slow growing version that you die with, not because of. 31% of men over the age 50 have prostate ca found at post mortem, as a incidental finding mostly.
Currently we can't really tell the difference between the 2 without quite invasive tests, which have potential side effects.
But it's the more aggressive cases that get publicised and inform public opinion.
Symptoms are also not such a great indicator either: most will be a benign condition called BPH. As I understand it, the cancers often start on the outside of the prostate and produce symptoms later.
I don't really mean to take away from the message of being aware of symptoms and discussing if you have concerns, but it is important to be aware that it is not clear cut and that there is no great screening test for it, yet.