Does PSA Promote Prostate Cancer?
Reviewed and critiqued by Stephen B. Strum, MD, FACPJune 2005
By William Faloon
Aging men should consider having their blood tested for DHT. If DHT levels are elevated, Avodart® drug therapy appears to be safe and effective not only for improving urinary flow symptoms, but more importantly for potentially reducing prostate cancer risk. Avodart® appears to accomplish these effects by reducing the growth-promoting effects of DHT on prostatic tissue, while decreasing the cancer-inducing properties of PSA by reducing PSA synthesis in the prostate gland.
Avodart® does have several downsides. At more than $3 per capsule, it is expensive. Moreover, a small percentage of men who use it have sexual dysfunction problems such as decreased libido (4%), impotence (7%), and a decreased volume of ejaculate (2%). The frequency of these side effects reportedly decline after six months of continued use of Avodart®.
Blocking PSA’s Detrimental Effects Naturally
There may be another way to protect the prostate gland against its own PSA. Since consuming green tea has been reported to lower the risk of prostate cancer, scientists investigated the effects of the green tea flavonoid epigallocatechin gallate (EGCG) on the expression and activity of PSA by prostate cancer cells. In addition to restraining PSA expression, EGCG inhibited numerous cancer-promoting properties of PSA in a dose-dependent manner. EGCG inhibited tumor-promoting activities such as degradation of type IV collagen. EGCG’s beneficial effects were at blood levels close to those measured in serum following ingestion of green tea.38 The study authors proposed that green tea extract may be a natural inhibitor of prostate carcinoma aggressiveness.
Effects of Soy on PSA Levels
Another potential way to lower PSA levels is to increase soy consumption. It has long been known that human populations that consume soy products have a lower risk of prostate cancer.9,39
Scientists have evaluated soy’s effects on PSA and other prostate cancer-related blood markers in men who had already developed prostate cancer.40 A group of 29 men scheduled to undergo surgical removal of the prostate were put on a 50-gram soy bread supplement or a 50-gram wheat supplement. The soy group saw a 12.7% reduction in PSA levels, whereas the wheat group experienced a 40% increase in cancer-promoting PSA. The free/total PSA ratio increased by 27.4% in the soy-supplemented group, compared to a decrease of 15.6% in the wheat group. (A higher free/total PSA ratio is a favorable indicator.) The investigators concluded that men who consume diets high in soy might have a reduced risk of prostate cancer development and progression.
Curcumin Induces Cancer Cell Suicide
Cancer cells do not follow normal, healthy cell suicide programs. Old cells need to die and be discarded, but cancer cells proliferate and grow.
Numerous studies over the past two years have identified specific mechanisms by which curcumin inhibits the growth of prostate cancer cells and then activates genes that tell cancer cells to self-destruct (also referred to as apoptosis).41,42 One study showed that curcumin reprograms prostate cancer cells so as to make them less likely to metastasize to the bone, while another study demonstrated that curcumin has radiation-sensitizing effects, making cancer cells more vulnerable to destruction by conventional radiation therapy.43,44 The research on curcumin is so promising that pharmaceutical companies are currently developing curcumin analogs that can be patented as anti-cancer therapies.45,46
Critical Importance of Annual PSA Testing
In 2004, the New England Journal of Medicine published an article indicating that the rate of increase in PSA is a more important predictor of mortality than the PSA reading itself. Men who showed a 2.0 ng/ml or greater increase in PSA from the previous year’s level were 10 times more likely to die within seven years.47 The researchers recommended that men over the age of 35 should have a baseline PSA reading and then retest each year to measure the rate of increase (PSA velocity). A sharp rise in PSA mandates the need for more comprehensive evaluation and treatment. Without previous PSA readings, it is impossible for your doctor to calculate PSA velocity. Optimal measurement of PSA velocity requires at least three PSA readings, with each obtained at least six months apart and tested at the same laboratory using the same PSA laboratory procedure.
In summary, accumulating data suggest that PSA is no longer merely a laboratory test of prostate gland activity. Instead, PSA is recognized as a functional protein: an enzyme that may facilitate prostate cancer cell proliferation, invasion, and metastasis. Taking steps to suppress PSA may reduce prostate cancer risk and progression. Meaningful reductions in PSA, as demonstrated in many of the studies cited in this article, appear achievable by using natural supplements like lycopene, soy, green tea, and boron, as well as through prescription drugs such as Avodart® or Proscar®, which normally reduce serum PSA levels by 40-50%.48-50
Low-Cost Blood Testing
A number of blood tests can identify correctable risk factors before clinically advanced disease becomes established. Most people test their blood to ascertain levels of cardiovascular disease markers such as homocysteine, C-reactive protein, LDL (low-density lipoprotein), and HDL (high-density lipoprotein).
While the PSA test has become well known, some men have been reluctant to have it done for fear that it will reveal a problem that cannot be easily corrected. Over the past few years, however, a significant number of publications have revealed safe methods of lowering PSA and potentially reducing prostate cancer risk.
Until June 1, 2005, Life Extension members can obtain comprehensive blood test panels at extra-low discounted prices. The popular Male Panel includes the PSA test, along with homocysteine, DHEA sulfate, C-reactive protein, and numerous other tests. It does not, however, include the dihydrotestosterone (DHT) test that would be of significant importance if PSA levels were in any way elevated.
High DHT levels stimulate the androgen receptor to induce greater PSA production.51 DHT also interacts with extracellular tissues to increase prostate cancer cell mobility.52 These and other findings may well be the basis for the reduction in prostate cancer development seen in men treated with inhibitors of DHT. The normal retail price for the DHT test is $60, but during the annual blood test sale, members pay only $23 for this test.
If you have delayed ordering your annual blood test panel, please do not wait any longer, as the Blood Test Super Sale ends on June 1, 2005. Now more than ever before, determining your PSA (and DHT) levels may dramatically reduce your odds of becoming a prostate cancer victim.
For longer life,
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