Everyman's Cancer?

Bill is 50 years old and had prostate surgery a year ago. Radical retropubic prostatectomy is typically performed on men with early-stage prostate cancer. Several months ago Bill had his nine-month post-surgery PSA (prostate-specific antigen) blood test.

“My one-year reading was above what is typical,” says Bill, “but my doctor thinks this is due to some prostate tissue that was left after surgery. I’ve started taking supplements, and I’ll have more checkups, just to make sure.”

The most frequently diagnosed cancer in Canadian males and the third most common cause of cancer-related death in men is prostate cancer. Because it is such a slow-growing cancer, it may never cause symptoms and is often only detectable by a PSA blood test, which measures levels of PSA, an enzyme produced by the prostate.

However, new research suggests that the test may result in overdiagnosis because it detects cancers that would never become life threatening. Some men with prostate cancer do not have an elevated PSA, and many men with an elevated PSA do not have prostate cancer. Some researchers even claim that if a man lives long enough, his prostate will eventually develop cancer.

Researchers are unsure what causes prostate cancer, but are learning what may slow its progress and perhaps prevent its onset. In 2000 a case-controlled study on the anticancer properties of legumes indicated that consumption of legumes lowered rates of prostate cancer. Numerous studies have shown that phytochemicals, such as the isoflavones genistein and daidzein, found especially in soy products, have anticancer properties. Soy products also contain protease inhibitors, phytic acid, lignans, phytosterols, and saponins, all of which appear to inhibit carcinogenesis.

Recently, research on prostate cancer has focused on the marriage of genetics and diet in a new arena of study called nutrigenomics. This new science seeks to understand how diet affects genetics, and researchers hope to someday design diets that delay the onset of genetically based disease. Prostate cancer has been the poster child for this type of research because of its high incidence and the relative longevity of the patients.

One of the largest prostate cancer studies ever conducted was the SELECT (Selenium and Vitamin E Cancer Prevention Trial) study, which included over 35,000 men. The study was designed to discover if selenium and vitamin E could prevent prostate cancer. While the jury may be out on its ability to prevent prostate cancer, selenium has been shown to enhance the efficacy of conventional medical cancer treatments by preventing the body’s resistance to the drugs.

Since his treatment ended, Bill has made changes in his life. “I take a vitamin mix that includes selenium, vitamin E, beta carotene, and vitamin C. I started drinking green tea instead of coffee, and I hit the gym three times a week to lift weights. I’m ready for the next 50 years.”

What’s a Normal PSA?

Normal blood levels of PSA depend on age and medical history.

• 3 or less is normal for men under 60
• 4 or less for ages 60-69
• 5 or less for over 70

A reading over 10 can indicate cancer or a benign infection. Men should discuss the limitations of the test—especially false-positive readings—with their health care professional.

See “Biochemical (PSA) Recurrence Probability Following Radical Prostatectomy for Clinically Localized Prostate CA,” The Journal of Urology (2003), at
cancerprostatehelp.org/download/jhnomo.pdf.

See also “High Prevalence of Complementary and Alternative Medicine Use Among Cancer Patients: Implications for Research and Clinical Care,” The Journal of Clinical Oncology (2005), at prostatehelp.blogs.com/prostatehelp/2005/04/high_prevalence.html.

For recent research on the PSA test, see “Assessing Risk: Does This Patient Have Prostate Cancer?” Journal of the National Cancer Institute (2006), at jnci.oxfordjournals.org/cgi/reprint/98/8/506.

For more on the role of soy see “Soybean Phytochemicals Inhibit the Growth of Transplantable Human Prostate Carcinoma and Tumor Angiogenesis in Mice” (1999), at jn.nutrition.org/cgi/reprint/129/9/1628.

See also the section on prostate cancer in “Soy isoflavone phyto-pharmaceuticals in interleukin-6 affections” from Belgium’s Ghent University (2004), available at
sparrowrose.com/food/soy025.pdf.

For more information on the SELECT study, see crab.org/select.