Prostate cancer psa

An Interview with Dr. Patrick Walsh

Whether it involves your father, son, brother, uncle, or best friend, prostate cancer at some point touches everyone's life. Fortunately, major inroads in prostate cancer screening, treatments, and prevention over the last two decades have dramatically improved the overall survival rate and quality of life for all victims of prostate cancer patients.

Today, the cadre ,of prostate cancer survivors include such well-known Americans as Bob Dole, Arnold Palmer, Harry Belafonte, Mike Milken, Rudy Guiliani, and Norman Schwarzkopf, all of whom have publicly shared their stories of hope and determination to promote screening, prevention, and early treatment.

The Post interviewed a leading authority on prostate cancer, Dr. Patrick Walsh from Johns Hopkins Medical School and developer of the nerve-sparing procedure for radical prostatectomy that has significantly reduced incontinence and preserved potency in prostate cancer patients. Dr. Walsh is also author of the highly readable Guide to Surviving Prostate Cancer.

Post: What is the role of diet and lifestyle in reducing the risk of prostate cancer?

Walsh: Prostate cancer is probably caused by oxidative damage. Reducing oxidative damage can involve dietary measures, such as adding antioxidants--selenium, vitamin E, and lycopene--to your diet. It could also be something as simple as eating an apple. A study in Lancet showed that an apple contained more antioxidants than many vitamin supplements.

Second, the effect of increased intake of calcium and fat from dairy products on increased risk of prostate cancer has been demonstrated in many studies. For example, men with high intake of calcium and/or dairy are more likely to develop advanced cancer.

There is also new information about a new enzyme called racemase, which breaks down the fatty acids in red meat and dairy products. Racemase is up-regulated tenfold in cancerous, as opposed to normal, tissue. If someone with prostate cancer eats substances with the fatty acid called phytanic acid--found in meat and dairy products--cancer cells get ten times more energy than from any other source, which is another reason why reducing the amount of red meat and dairy products in your diet is a very wise thing to do. Reducing these foods is heart-healthy as well.

Post: Scientists often underscore the decreased incidence of prostate and other cancers among men from Asia, where the diet is low-fat.

Walsh: There is a strong link with environment. Asian men who live in Asia have a two percent lifetime risk of developing prostate cancer. When these men move to the Western culture and live here for more than 25 years, their risk for prostate cancer approaches that of Caucasian males in the U.S. Environment relates to diet, sunlight, and other factors that may affect your risk for prostate cancer during your adult life. If we identify those factors, we should be able to reduce the incidence of prostate cancer. Until we've completed these studies, rational preventive measures for men include getting adequate amounts of antioxidants and reducing dietary intake of fat, especially fat from red meat and dairy products.

Post: Do omega-3 fatty acids from certain fish help reduce the inflammatory process?

Walsh: A very interesting article was just published in the NEJM from three Hopkins' scientists--Bill Nelson, M.D., Ph.D.; Bill Isaacs, Ph.D.; aria Angelo DeMarzo, M.D., Ph.D. As mentioned previously, we believe that prostate cancer is caused by oxidative damage. The sources of oxidative damage, as we have spoken about, are both dietary and metabolic, from cell metabolism.

A third and potent source of oxidative damage is from inflammation. There is a lot of inflammation in the prostate. Dr. DeMarzo has investigated and shown that inflammation in the prostate is associated with precancerous lesions. He has termed it PIA--proliferative inflammatory atrophy. Next to the areas of inflammation, you can find areas of atrophy. The atrophic cells are not just sitting there asleep, however; they are rapidly turning over and have genomic abnormalities. Next to those cells, you often find a premalignant lesion called PIN. What causes this inflammation?

Johns Hopkins' researcher Bill Isaacs and I have been looking at hereditary prostate cancer genes. Last year, we identified two genes that occur in a small number of families that cause prostate cancer; these findings were published in articles in Nature Genetics. These two genes are normally responsible for protecting you against infection. A whole new avenue of thinking about prostate cancer is opening up: Could prostate cancer be caused by infection, like others such as stomach and liver cancer? The infections would be chronic, smoldering, and cause chronic inflammation, which could lead to oxidative damage--a whole cascade of events.

Post: What is the difference between a total PSA and free PSA test?

Walsh: PSA is an enzyme. If you think of the PSA enzyme as a pair of scissors circulating in the serum, they would chop everything. In the serum, PSA circulates in a bound form like scissors inside a case. When you measure total serum PSA, you are measuring bound PSA.

If an arm of the scissors, for example, was broken, we can refer to that as "free" PSA, which can't cut anything and circulates freely. For reasons that no one as yet understands, the higher the percentage of free PSA, the more likely you are free of cancer. Conversely, the lower the free PSA, the more likely it is you have cancer.

Post: If a man has an elevated total PSA, should the test be repeated?

Walsh: Yes. Today, if a man has an elevated PSA, the test should be repeated, and a recent article in JAMA confirms this finding.

When repeating the test, I have men refrain from sexual activity for several days, forgo a rectal examination before the PSA test, and perhaps take antibiotics for two weeks to make sure that there is not a lingering infection. The PSA test is then repeated. If the PSA remains elevated, a biopsy may be indicated. If free PSA levels are low, it indicates that the elevated PSA may indeed be coming from cancer, and you need a biopsy.

PSA of course refers to "prostate" specific, not "cancer" specific, so elevations in PSA can be caused by cancer, benign enlargement (BPH), or infection. But if the PSA level is elevated, you have some sort of prostate disease.

Post: Would it make sense to refrain from sexual activity and delay the DRE until after your initial PSA test?

Walsh: Ideally, you should. Often, a person doesn't know that he is being tested for PSA. Someone draws a blood sample, and the first thing you know, someone says your PSA is up.

Post: If a PSA is elevated and the biopsy reveals no cancerous cells, are patients off the hook?

Walsh: If the biopsy is negative, it does not necessarily mean that they don't have cancer, because it is possible that the area of cancer was not sampled. They are not totally off the hook. They need to be followed by a good doctor, who can call the shots.

Post: At what age should men begin screening for prostate cancer?

Walsh: The current recommendation is 50 or, if at high risk--African-American or with a strong family history--age 40. A study by Johns Hopkins' researcher Dr. H. Ballentine Carter that was published in JAMA investigated a model for screening that would save the most lives and money. The model that saved the most lives at the least cost promoted the first PSA beginning at age 40, the next at age 45. Then when men reach age 50, a PSA would be done every other year. Of course along with the PSA, you need a rectal exam as well, because 25 percent of men with prostate cancer will have a low PSA.

Post: When faced with surgery for prostate cancer, how important is it for men to select a center where the procedure is performed often?

Walsh: More important than that is to find a surgeon who has dedicated his life to performing the operation well. When you look at the outcomes of radical prostatectomy in the literature, you will find results where potency and continence is quite high, while in others it is quite low. The difference is in the way the operation is performed.

Someone from Korea watched me perform the operation today. He has done this operation himself, yet had never seen the nerves like this before, so you can imagine that his patients do not have the same outcome.

To improve the results of surgery around the world, I have spent the last several years putting together a video presentation of this operation--a DVD--that is over two hours long, with excellent video footage and illustration. I am giving this DVD to every urologist in the world who wants it, free, with the idea that the whole field would be better if more people knew how to do this operation well.

For the best outcome, find a urologist who does these operations frequently and who can answer some of the questions that I bring up in my book: