5 yrs ago my psa was 5, now it's 15. when is intervention necessary?

Depends on your age: The discussion of intervention depends on your age and symptoms.You need to sit down with your urologist and discuss this. If you are 50 the answer is intervention now. If you are 70, then the answer may be different.

Possibly never but..: It may well be worthwhile to be tested to see if you have prostate cancer, which is likely (but not certain) with a psa that high, but even if you do have prostate cancer, treatment is usually not necessary and often does more harm than good. Most men, if they live long enough, will develop prostate cancer, but most will not die from it. But it would be wise to see a urologist. See my comment:.

Worth followup: Controversy re: psa and rx for prostate ca. Is the rx worse than the disease? Individualized don't know ur age, family history, race, symptoms, digital prostate exam. Psa is more a measure of prostate volume than specifically for cancer cells. Dramatic changes should get followup, get a free/total psa, rectal exam, maybe more, e.g. Sono. See urologist. Maybe enlarged but no ca, .

Now: If your psa was being monitored yearly then this large jump would have been seen gradually. Normal psa is less than 4. Trends and the actual number is both important. See a urologist for rectal exam and discussion about a prostate biopsy.