This was a comment/question a few days ago….this issue is confusing but I think I can simplify it-here goes.
- The ongoing debate about the PSA has to do with pretreatment decision-making. The PSA is often times elevated before the diagnosis of prostate cancer is made for many reasons other than prostate cancer. So some want to “throw the baby out with the bath water.” If you come into my office and you are referred to me for an elevated PSA (anything higher than 4) a couple of things could happen. I might repeat it, I might give an antibiotic and repeat the PSA several weeks later, or if on rectal exam there is an abnormality-I would recommend a biopsy then without repeating the PSA (the rectal exam trumps the PSA if the prostate feels abnormal.)
- If the PSA is elevated pre diagnosis (by this I mean at this point we don’t know if there is cancer or not) I put a lot of weight on a strong family history of prostate cancer. So if you show up in my office with an elevated PSA and your father and brother have had prostate cancer…I’ll recommend a biopsy.
- So before the diagnosis of prostate cancer in that patient with a high PSA…if there is no family history and the rectal exam is normal..it is a good thing to “drag your feet a bit” and repeat the value after some time or antibiotics and if still elevated…proceed to biopsy.
- The PSA is variable in the man who is pre treatment and pre diagnosis, and is one of many arrows in the doctor’s quiver.
- Obviously if the patient is in bad health, old and the gland is normal to exam and there is an elevated PSA from a year ago and it is about the same as the one you have now…that’s a reason to defer a biopsy.
- The reason I am an advocate of a PSA at 40…it serves as baseline. We are less excited about a patient whose PSA may be elevated but has been that way for years, than the guy whose baseline for years has been 4 and now it is 7. (Vel0city change.)
Where the PSA is variable but helpful pre treatment and pre diagnosis…it is an excellent marker post treatment..i.e “you can take it to the bank.”
- If you have had the prostate removed the PSA should go to almost zero… with the ultrasensitive method it should be .02 or so.
- If after remove the value goes to near zero, it should stay there.
- If after removal the value goes to .02 and then begins to rise over time…that is evidence of recurrence.
- How fast it begins to rise (doubling time) is an important prognostic factor.
- I tell patients this: “It’s best when the PSA goes to zero and stays there. The next best thing is that if it does begin to rise, that it rises very slowly.)
- For radiation, and things like cryo, HIFU, nanoknife, proton….the PSA usually doesn’t go near zero. It will decline usually to .5 or less. This is called the nadir…and for these treatments if PSA goes to this level and stays there or less…it is considered a cure.
- If the PSA goes up following these treatments and the trend continues…that represents a recurrence of disease.
- There is an exception in that radioactive seeds often times cause a PSA bump that occurs around 18 months and then will go back down. It’s tricky time but during that interval the PSA is repeated until it either goes back down or continues to rise….confirming either the bump or recurrence.
- So…the PSA is a very dependable post treatment tool. The time from the treatment and rate of change give an indication of how aggressive the prostate cancer is and whether it will metastasize.
Finally…When the PSA is really high….if normal is 4 and the patient’s PSA is say…over 40. (It can be in the hundreds.)
- If a man presents with a PSA over 40 and there is no other reason for it to be elevated (prostatitis) it is very likely that there is prostate cancer, an abnormal exam, and metastatic disease.
- If one has been treated for prostate cancer and the cancer has come back and the PSA is now say…10. If that patient is treated with hormonal therapy…in the majority of cases the PSA will go to zero. In this case the PSA is a very valuable test for determining if hormonal therapy is working and when it is not.
- When PSA continues going up on hormonal therapy, this is a bad prognostic sign. This is called “hormone refractory” and it is usually when the medical oncologist gets involved. This is also where the newer drugs that are so expensive will come into play. (Provenge)
Summary on the PSA test
- Pre diagnosis and treatment–helpful but variable—part of the decision-making process but not a stand alone type test.
- Post diagnosis and treatment–a very reliable, helpful test to help assess both response to treatment and the recurrence of disease.
- In case of recurrence, it is very reliable and valuable in determining if hormone therapy is working , if hormone therapy isn’t working , in the timing of medical oncological referral by the urologist.