I would like to speak about my individual case for a moment, rather than statistics.
I was not screened - which is what the main uproar is about - but rather tested after coming to my primary care doc with a complaint. There is a difference.
The complaint was increased night time urination. It was almost certainly a result of my tendency to hypochondria along with a little BPH.
So PSA testing resulted in me going to see a urologist years before I would have otherwise. He immediately did a biopsy, and did not try antibiotics, or watch my PSA velocity (this is a main complaint of the PSA pioneers Ablin and Stamey as I understand it - going straight to biopsy after one PSA).
Eventually, after several years, lots of PSA tests, and three biopsies, cancer was found. It was found by the trend, though--a sudden jump after a period where it was low--along with a positive DRE. It appears, based on Gleason and doubling time, that it was not indolent. It would have, and may still, kill me before other causes like my high cholesterol or blood pressure.
Did mass PSA screening play a role in saving me? No. It most definitely did not, because I did not get screened and I was years away from that. Testing may have played a role - and if you read PSA discoverer Ablin's comments (New York Times, March 10, 2010)carefully, he does not dispute that there is a role for testing, especially in high risk cases, nor does he dispute the value of PSA in post-treatment monitoring.
Again, PSA as a diagnostic tool *may* have helped me. Maybe I've been cured of a disease that would have slipped by, otherwise, and killed me early, a la Fogelberg or Zappa. But here's the thing - I don't know. It's possible that I have gone through surgery and radiation and in spite of my good results so far, my PSA will come zooming back and in the end, the result will be the same, maybe even the same timeline.
Only a lot of time will tell. I read, over and over again, on multiple forums, from men who have just been treated, that PSA screening has saved them. In some cases, they weren't really screened, but tested after presenting with a complaint. And in a lot of cases, they are saying that PSA testing saved them when it's too early to know that with any certainty. When Stamey spoke at the meeting I went to, there was a lot of anger from the men in the room, because what he was saying was essentially that although everyone hoped they had been saved by PSA, given enough time, a significant portion would find that wasn't the case, or that some of them had been "saved" from a disease that would have never threatened them.
Again, I'm not saying that I agree or disagree with the PSA pioneers, and I hope that PSA played a role in saving my life. The bottom line is, however, that I don't know.