Frequently Asked Questions

Prostate Specific Antigen (PSA)

Q: My PSA is 4.4. What is PSA?

A: PSA stands for Prostate Specific Antigen. The word ‘Specific’ means that this enzyme is produced only by prostate cells – whether normal prostate cells or prostate cancer cells. No other cells – lung, intestine, liver, etc. – make PSA. The purpose of PSA is to keep semen (the white substance ejaculated during sexual intercourse) liquefied. PSA is also leaked into the bloodstream by normal prostate cells and can be measured by a simple blood test as was done with your PSA.

Q: What is the usual amount of PSA in the bloodstream made by normal prostate cells?

A: We used to think that a PSA below 4.0 was normal. Now, with more experience, we recognize that there is no such thing as normal PSA. Most men who do not have prostate cancer will have a PSA below 2.0. However, you can have cancer with a PSA below 2.0. On the other hand, as men age and the prostate becomes enlarged by more normal cells, more PSA is produced. Because of this, most men with a PSA below 10 do not have prostate cancer.

Q: What happens to a man’s PSA when he gets cancer?

A: A prostate cancer cell typically makes a lot more PSA than a normal prostate cell. As a result the PSA increases just as yours did. Yours was 2.3 two years ago and now is 4.4. Usually, but not always, the amount of PSA you have indicates how much cancer you have. However, the amount of PSA does not always show how much cancer you have. Sometimes cancer cells don’t make much PSA. We have seen men with PSA below 1.0 with prostate cancer.

Q: What is the average PSA level when prostate cancer is found in a biopsy?

A: The average is 7.4 ng/ml. So, your PSA of 4.4 is below average which is good suggesting you have less cancer than average. We divide men with prostate cancer into four PSA groups. The table here shows these PSA Groups and the percent of all men with prostate cancer divided into the groups. As you can see, 62% of men with prostate cancer have a PSA between 4.1 and 10, which is where your PSA is located.

Table-4

Q: If most men with a PSA below 10 do not have prostate cancer but most men with prostate cancer also have a PSA below 10, how do you know if a man’s PSA rise is from cancer or not?

A: You don’t. This is the limitation of the PSA test. An elevated PSA can be produced by prostate cancer, but it also can be produced by other causes such as benign prostate hyperplasia (enlargement of the prostate or BPH) and prostatitis (irritation or inflammation of the prostate). In fact, most elevated PSAs are not due to cancer but are due to BPH (Benign prostatic hyperplasia) or prostatitis.

Q: How did my doctor know what was causing my PSA to go up?

A: He didn’t. He very wisely saw that your PSA had changed a lot: from 2.3 to 4.4. There is no way to determine why your PSA elevated except through a prostate biopsy which is why your internist sent you to a urologist.

Q: Does PSA tell you where the cancer cells are located? If I had prostate cancer cells in my left shoulder bones, would those cancer cells make PSA?

A: Yes, a prostate cancer cell in your left shoulder could make the same amount of PSA as a cancer cell in your prostate. PSA gives no indication of where the cancer cells are located in your body. For example, let’s say with your PSA of 4.4 that you have 100 cancer cells in your body producing PSA. If all 100 cells are located inside your prostate, your PSA would be 4.4. If 90 were inside the prostate and 10 had leaked outside the prostate into your left shoulder, you would still have a PSA of 4.4. PSA does not show where cancer cells are located in your body.

Q: I have read in the newspaper that men should no longer have a PSA blood test for prostate cancer. What do you think of this controversy?

A: This controversy has been caused in recent years due to the finding that most men with an elevated PSA do not have prostate cancer. Thus, in hindsight, most prostate biopsies do not show cancer. Also, many men have a very slow growing disease that does not need treatment which we will talk about later. And, many men may die of other causes, such as a heart attack, before their cancer bothers them. To make a long story short, questions have arisen about the cost-effective value of the PSA test as a screening tool for prostate cancer. It is the same argument that some doctors have raised about mammographic screening for breast cancer for women with the argument that most mammograms are wasteful.

I respect the analysis by doctors who recommend against getting routine PSA screenings, but I disagree completely. We have been treating prostate cancer since the mid 1970s, well before the PSA test was developed in 1987. Before the PSA test, we had no way to find early cancer. Back then, most men had their cancer discovered when it was advanced, often not curable because it had already spread, for example, to their bone. They were first seen by their doctor because of a backache due to prostate cancer destroying their spine and died a painful death one or two years later. These men could have lived many more years were it not for their cancer death. A lot more men died of prostate cancer back then than do today, yet prostate cancer is still the second most common cause of cancer death in men, behind lung cancer. Everything changed beginning in 1987 with the use of the PSA test because we were then able to find prostate cancer very early while it was still curable. A lot less men die of prostate cancer today than before the PSA test. The PSA test is not perfect, but it is better than anything else. We do not want to go back to 1970 medicine. To put this on a personal note, I get a PSA test every year and I do not care about what anyone else says. If my PSA changes, I would then have a prostate biopsy, just like you did, to see if I have cancer and, if so, how aggressive is the cancer. That way I could detect the cancer early and have the appropriate management before giving my cancer a chance to spread. I would not want to die because of prostate cancer like 30,000 men do each year even today with the PSA test. If I can prevent death from cancer, I think it is worth getting regular PSA tests.

 


 

Q: I have a weak, slow stream. If I did not get a PSA test, would my urine symptoms cause my doctor to check for cancer?

A: No. Prostate cancer rarely causes any urine symptoms. The urinary symptoms you are having are probably from compression (squeezing) of the urethra due to an enlarged prostate, called BPH. The first symptom of prostate cancer is usually bone pain from cancer cells that have spread to bone, such as your spine, and then you are not curable.

Q: If I quit doing a PSA test, could my primary care doctor find prostate cancer early by my yearly physical exam?

A: Not likely. Most men who have prostate cancer, just like you, have a normal prostate exam. Prostate cancer is usually more advanced when you find it on physical exam.

Q: What would have happened if I had not gotten a PSA test that showed my PSA increase to 4.4?

A: With your Gleason 4+3 cancer, which is an aggressive cancer, it would have continued to grow and eventually spread throughout your body without you knowing anything about it. You would then have incurable cancer and later die. Without the PSA test to screen for prostate cancer, we go back to practicing medicine like in the 1970s.

Q: I have heard that men often die of something else and not because of their prostate cancer. Can you tell me more?

A: That certainly happens. If you were to die of a heart attack in the next few years, doctors and insurance companies against PSA testing would say: This man had prostate cancer but died of something else which shows that the PSA test was needless. However, what happens if you don’t die of a heart attack? By staying trim, exercising, and not smoking you can live for 20 or more years. Thus, you could live long enough to die because of your prostate cancer. From the time of biopsy, the average time to death for men who die because of prostate cancer is 8 years but can range from less than a year to 25 or more years later.