Deepak Chopra, MD - Weekly Health Tip: Prostate Cancer: Screening and Prevention
Chances are good that you or someone you know has had experience with prostate cancer. One in six men are diagnosed with the disease every year. But here’s the good news: Only 1 in 36 men who are diagnosed with prostate cancer dies from it. When cancer forms in the prostate, it often grows very slowly, and the person ends up dying of another disease. Still, in its aggressive form, prostate cancer is serious business: It kills 30,000 men each year in the U.S. and is the second most common cause of cancer death among men (after lung cancer) (1). No doubt you have heard about the debate surrounding screening for prostate cancer. What better time than Men’s Health Week to learn about the issues with screening and find out how you can reduce your risks of getting prostate cancer.
A Challenge to Diagnose The prostate is a walnut-size gland found in men that helps produce semen. As most men get older, the prostate becomes enlarged. This can cause urinary problems, but it has nothing to do with cancer. Sometimes, though, tumors develop in the prostate. Often they grow so slowly that they never require treatment. But some tumors can be lethal, and those are the ones that doctors aimto detect.
The current test used to screen for prostate cancer is a blood test called PSA. It measures the amount of a protein called prostate-specific antigen (PSA) in the blood. The test is not perfect, though, even when used in combination with a rectal exam. The problem is that PSA screening can indicate the presence of cancer when there is none (men with an enlarged prostate or other benign conditions can have elevated levels of PSA in their blood). The test can also underestimate the aggressiveness of cancer when it does detect it (2). That’s one reason why experts disagree about the efficacy of screening. Scientists are currently developing new diagnostic technologies that will allow early, accurate detection of prostate cancer, such as using biomarkers that can be measured in blood or urine. PCA3 and Gene Fusion are two promising biomarkers being researched due to their close association with the presence of prostate cancer (3). Hopefully these biomarker tests will be able to accurately detect prostate cancer, but until this research becomes more robust, diagnosing the disease remains a challenge.
To Screen or Not to Screen Those who support PSA testing cite studies that link screening to a decrease in mortality from prostate cancer. They say that it’s best to detect aggressive prostate cancer early on, when it’s easier to treat (2, 4). They also note that deaths from prostate cancer have declined four times faster in the U.S. than in Britain since PSA screening was widely introduced in the United States. Currently, almost 60% of men in the U.S. over 50 get screened for prostate cancer using the PSA test, vs. fewer than 10% of men in the UK (5).
Those who argue against testing say that statistics that link screening to decreased mortality are misleading, and are the result of an increase in the diagnosis of low-risk cancers that aren’t fatal to begin with. They also say the decline in mortality rates in the U.S. compared to the U.K. may be due to factors other than screening, including different treatment practices and the greater use of hormone therapy in older men. Perhaps their most powerful argument against testing is that screening can lead to unnecessary treatment for slow-growing tumors that would not have caused any problem (4, 5). Treatments for prostate cancer, which include surgery and radiation, can have serious, long-lasting effects, including incontinence and impotence. A 2009 study of European men found that 48 men were diagnosed and treated for each prostate cancer death prevented (5, 6).
Know Your Risk Factors Confused? You aren’t alone. Medical organizations give varying advice about screening. The American Cancer Society doesn’t recommend routine screening for men of average risk, although it does suggest talking to your doctor about screening sometime between the ages of 40 and 50, depending on your risk factors. The Centers for Disease Control and Prevention considers the evidence insufficient to determine whether the benefits of screening outweigh the harms.
A recent study of 12,000 Swedish men sheds some new light on the debate. The study suggests using an initial screening at age 45-50 to determine the number of future screenings. Men with very high PSA levels would get screened every year; those with low levels could wait five years to get retested; and if PSA levels remained low, they could get their final test at age 60. The study needs to be replicated, but it suggests that many men may need just three screenings over their lifetime (6).
Until a more accurate test is available, your best bet is to learn your risk factors for prostate cancer and then talk to your doctor about the pros and cons of PSA screening. Risk factors include age (after age 50, your chances of having prostate cancer increase significantly); ethnic background (African-American men are at higher risk); having a close family member with the disease; eating a diet high in fat, especially animal fat.
Prevention While there is no surefire way to prevent prostate cancer, research shows that diet and lifestyle changes may help reduce your risk of the disease. Eat a low-fat diet rich in fruits, vegetables, and fish (7). Avoid eating more calories than you need, maintain a healthy weight, and limit your intake of red meat, processed meat, and grilled meat. A 2011 study concluded that weekly consumption of three or more servings of red meat, 1.5 or more servings of processed meat, and 1 or more servings of grilled red meat were each associated with a 50% increased risk of developing advanced prostate cancer (8). Use alcohol in moderation—no more than two drinks a day for men (9). Consider adding soybeans and soy-based products and green tea to your diet. Soybeans contain chemicals that behave like the hormone estrogen, which may help prevent prostate cancer. Green tea contains antioxidants that may help fight cancer (9). And studies show that there may be a connection between chronic inflammation and prostate cancer, and that both green tea and soy products have anti-inflammatory effects (10).
Learn more about Prostate Cancer
4. Borofsky MS, Makarov DV. Prostate-specific antigen (PSA) velocity: a test of controversial benefit in the era of increased prostate cancer screening. Asian Journal of Andrology. 2011; advance online publication (May 2011): 1-2.
7. Ma RW, Chapman K. A systematic review of the effect of diet in prostate cancer prevention and treatment. Journal of Human Nutrition and Dietetics. 2009;22(3):189-199.
8. John EM, Stern MC, Sinha R, et al. Meat consumption, cooking practices, meat mutagens, and risk of prostate cancer. Nutrition and Cancer. 2011;63(4):525-537.
9. Mayo Clinic
10. Hsu A, Bray TM, Ho E. Anti-inflammatory activity of soy and tea in prostate cancer prevention. Experimental Biology and Medicine. 2010;235(6):659-667.