According to three recent studies, PC-SPES, a traditional Chinese herbal
preparation, may alleviate symptoms of advanced prostate cancer in patients,
including those who have failed conventional therapy. PC-SPES is a mixture of
extracts of eight distinct herbs. Commercially available since November
1996, PC-SPES is being used more and more in conventional medicine for the
treatment of prostate cancer.
Prostate cancer is a malignant tumor that develops in the prostate gland, a
walnut-sized male sex gland that produces the thick fluid that forms part of
semen. The disease can eventually spread through the blood to other organs,
bones, and tissues. Fortunately, prostate cancer tends to be slow growing
compared to many other cancers. For example, it is common for elderly men to
have prostrate cancer without experiencing any symptoms. As many as 90 percent
of all prostate cancers remain dormant and clinically unimportant for decades.
However, when the disease finally does manifest itself, it can be deadly.
In the United States, prostate cancer is the most commonly diagnosed cancer
in men over 50 and the second leading cause of male cancer deaths, after lung
cancer. While the incidence of prostate cancer, especially among younger men,
has begun to decline since 1994—largely due to early
detection and more accurate screening tests, the risk remains very high for
African American men. As a group, their risk for prostate cancer is 66 percent
higher than it is for American men of European ancestry. On the other hand,
Native Americans and Hispanic Americans have relatively low rates.
Interestingly, prostate cancer is rare in many parts of Africa, with the lowest
rates found in Israel, Russia, and Japan. Scientists believe that diet, stress
levels, and other environmental factors may help to explain these
differences.
One indication that a man may have prostate cancer is elevated Prostrate
Specific Antigen (PSA) levels. When surgery and radiation therapy are not able
to eliminate the cancer, doctors may attempt to reduce or eliminate the tumor
through lowering male hormone levels. This entails treatment with female
hormones or an operation to remove the testicles. If the approach of lowering
male hormones is successful, the patient has androgen-dependent prostate cancer.
If it fails, the man has androgen-independent prostate cancer, which has a
poorer chance of recovery.
In a joint study by UCSF Comprehensive Cancer Center and Memorial
Sloan-Kettering Cancer Center, doctors used PC-SPES to treat 32 patients with
androgen-dependent prostate cancer and 35 patients with androgen-independent
prostate cancer. Androgen is a male hormone. All those in the androgen-dependent
group reported a greater than 80 percent decrease in PSA levels. More
importantly, over half of those in the androgen-independent (the more severe
form of prostate cancer) group reported a PSA decrease of more than 50 percent.
Two other studies—one from the Brander Cancer Institute
and another from Columbia University, suggest that the complex composition of
herbal material found in PC-SPES may block the cancerous cell growth. In all
three studies, PC-SPES seemed not only to arrest the development of the disease,
but also to improve quality of life in patients suffering from advanced prostate
cancer.
Since the usual treatment for prostate cancer (surgery, radiation therapy,
and hormone treatment) often has undesirable side effects, PC-SPES's relatively
mild side effects make it particularly appealing. In elderly men, especially,
one wonders if the risks associated with conventional treatment for prostate
cancer are worth the potential benefit at that point. Although the herbal
mixture's effectiveness needs further validation, its apparent ability to
improve quality of life and arrest cancer development without serious side
effects is an important consideration. Researchers are evaluating whether
PC-SPES, because of its relatively few side effects, should be the treatment of
choice in situations in which the patient is already quite advanced in years.
Especially in light of potentially harmful herb-herb and herb-drug interactions,
further study will be needed to establish quality control, and standardization
in the use of complex preparations such as PC-SPES.
