September is National Prostate Cancer Awareness Month, so I thought that a discussion of prostate cancer and preventative measures would be an appropriate topic to write about as the month approaches its end. As a urologist and a wellness advocate, this subject is very dear to my heart.
Prostate cancer is the second leading cause of cancer-related deaths among men in the USA. The burden of this disease is felt not only by those men diagnosed with this disease, but also by their partners, relatives and friends who are key elements in their emotional support system.
Prostate cancer is the most common non-skin malignancy among men in most Western populations (240,000 estimated new cases in 2011 in the U.S.), and is the second leading cause of cancer death among U.S. men (34,000 estimated deaths in 2011). To put this in perspective, heart disease causes more than 800,000 deaths per year in American men and is the leading cause of death in men with prostate cancer. Many more men die of heart disease than of prostate cancer, and even in the population of men with prostate cancer, many more men die with it than of it.
The three major risk factors for prostate cancer are age, race, and family history. The likelihood of developing prostate cancer increases with the aging process, thought to be on the basis of gradual accumulation of DNA mutations due to incremental oxidative damage (literally “rusting”) of prostate cells. With each decade of aging, the incidence of prostate cancer increases appreciably.
In terms of race, African-American men have the highest reported incidence of prostate cancer in the world, with an incidence of 1.6 times that of Caucasian men in the United States; additionally, mortality is 2.4 times higher for African American men. On a worldwide basis, the highest incidence is in North America and Scandinavia and the lowest incidence is in Asia.
Prostate cancer tends to run in families, so it is prudent for male children of those with prostate cancer to be checked on an annual basis starting at age 40 (with a PSA blood test and digital rectal exam). With respect to familial prostate cancer, risk increases according to the number of affected family members (the more affected, the higher the risk), their degree of relatedness (brother and/or father affected confer a higher risk than cousin and/or uncle), and the age at which they were diagnosed (relatives of patients diagnosed younger than 55 years old are at highest risk). Generally speaking, if you have a brother or a father with prostate cancer, your risk of developing it is doubled. If you have three family members with prostate cancer, or if the disease occurs in three generations in your family, or if two of your first-degree relatives have been diagnosed at an age younger than 55 years, then you have a good likelihood for hereditary prostate cancer, which confers a 50% risk of developing the disease.
My father, a retired urologist, was diagnosed with prostate cancer at age 65 and underwent curative surgery and is currently 80 years old and thriving. For this reason, I have been very diligent in seeing my internist annually for a prostate examination and a PSA blood test. Additionally, I have been proactive in taking a medication to decrease my risk of prostate cancer.
Prostate cancer is unique among solid tumors in that it exists in two forms: a latent form (evident on autopsy studies, but not causing an abnormal digital rectal exam or PSA), which is present in 60-70% of men older than 80; and a clinically evident form (causing an abnormal rectal exam or elevated PSA), which affects approximately 1 in 6 men in the United States. Overall, men have an approximately 17% chance of being diagnosed with prostate cancer and a 3% chance of dying from it. This high ratio of prostate cancer incidence to mortality suggests that a portion of the cancers are minimal or indolent, non life-threatening conditions.
Currently, most prostate cancers are detected on the basis of a PSA elevation ranging from 2.5-10 ng/ml. Widespread PSA testing has resulted in the increased diagnosis of prostate cancer and a downward stage migration to non-palpable, organ-confined cancer with a parallel reduction in deaths—as opposed to the pre-PSA era, when most cancers were detected on the basis of a palpably abnormal digital rectal exam and were at a more advanced stage at presentation.
It is very important to know that when detected early, prostate cancer is highly curable. In the USA, more than 90% of men diagnosed with prostate cancer survive at least 10 years after the diagnosis is made. Even when not discovered early, it is a very manageable condition. In general terms, prostate cancer is a relatively slow-growing process. Although most prostate cancers diagnosed at an early stage often have an indolent course, local tumor progression and metastases may certainly develop in the long term; therefore, early treatment is an important consideration for men with a general life expectancy exceeding 10 years.
Localized prostate cancer typically causes no symptoms and is typically diagnosed by a biopsy done because of a PSA elevation, an accelerated increase in the PSA over time, or an abnormal digital rectal examination. Non-palpable cancers, i.e., those picked up by virtue of a PSA elevation or accelerated PSA velocity, now account for 75% of all newly diagnosed prostate cancers. Although screening for prostate cancer remains somewhat controversial because of a lack of studies demonstrating a decrease in mortality in screened populations, the observed trends in PSA-driven detection of prostate cancer at earlier stages and declining mortality where screening is common provide strong inferential evidence that screening is beneficial.
Wouldn’t it be wonderful if we could prevent the occurrence of prostate cancer? It certainly would make my job a whole lot easier. Unfortunately, we are not there yet—but we do know a thing or two about lifestyle measures that can be pursued to maintain health and wellness in general and to help mitigate the chances of developing prostate cancer.
When Asian men (the ethnic group that has the lowest incidence of prostate cancer) migrate to Western countries, their risk of prostate cancer increases substantially over time. So it is clear that environment plays a strong role in the genesis of prostate cancer and it is not just a simple matter of genetics.
Unquestionably, a coronary artery-clogging Western diet high in animal fat and highly processed foods and low in fruits, vegetables, legumes and whole grains is associated with a higher incidence of many preventable chronic health problems including cancer. A heart-healthy, colon-healthy diet is a prostate-healthy and life-healthy diet. A healthy diet combined with a healthy lifestyle, will afford us our best opportunity at minimizing heart disease, diabetes, and a host of cancers. This means weight management; the avoidance of obesity; healthy eating with abundant fruits and vegetables (chock full of antioxidants, vitamins, minerals and fiber) and real food as opposed to processed foods; consumption of animal fats and dairy in moderation; avoidance of tobacco and excessive alcohol; and plenty of exercise. And if we do develop prostate cancer, we will be in stellar physical shape and will heal that much better from any intervention necessary to treat the prostate cancer. Good nutrition and exercise helps in part by inhibiting oxidation and inflammation, factors that contribute not only to prostate cancer but also to conditions such as heart disease and osteoarthritis.
Michael Pollan, a journalism professor at the University of California, Berkeley and author of The Omnivore’s Dilemma, summarized in a most succinct way the answer to the question of what humans should eat, in his seven words: “Eat food. Not too much. Mostly plants.” By food, he means a nutritional substance that your grandmother would recognize as food, not a food-like highly processed substitute. Not too much is pretty obvious. A mostly plants-based diet will result in the consumption of a moderate amount of calories and plenty of fiber and anti-oxidants.
In addition to recommending a regimen of healthy eating and regular participation in exercise, there are medications that can help prevent the occurrence of prostate cancer. The presence of precursor lesions such as high grade prostate intraepithelial neoplasia (HGPIN) many years before the onset of prostate cancer, coupled with the increasing prevalence of prostate cancer with the aging process, suggest that the process of developing cancer takes place over a protracted interval of time. In fact, it is estimated that it takes many years—often more than a decade—from the initiation of the initial mutation to the time when prostate cancer becomes clinically manifest with either a PSA elevation or an abnormal digital rectal examination. In theory, this provides the opportunity for intervention before the establishment of a cancer.
The Prostate Cancer Prevention Trial was a clinical trial that tested whether Finasteride, which induces a deficiency of the enzyme 5-alpha reductase, would prevent prostate cancer. This trial was based upon the fact that prostate cancer does not occur in the absence of testosterone and that men with a congenital absence of 5-alpha reductase (that functions to convert testosterone to the activated form, dihydro-testosterone) do not develop benign or malignant prostate growth. This 7-year study involved almost 20,000 men who were randomly assigned to Finasteride or placebo. The study was terminated 15 months early because a 25% risk reduction for prostate cancer was achieved on Finasteride. The other finding was that the prevalence of higher-grade cancers was slightly higher in the Finasteride group (6.4% vs. 5.1%); however, Finasteride is known to change the pathological appearance of the prostate in such a way as to make determination of an accurate grade difficult.
A number of years ago, I was given the disheartening news that I had sunburn on my crown! A balding pate frankly did not appeal to my sense of vanity! After topical Minoxidil (Rogaine) proved ineffective, I started taking Propecia (a.k.a. Finasteride) every morning. Lo and behold, my thinning crown filled in and ultimately I had a full re-growth of hair. When the Prostate Cancer Prevention Trial report came out revealing a 25% risk reduction for prostate cancer associated with the use of Finasteride, this cinched it—particularly insofar as my father had been diagnosed with prostate cancer. Finasteride is a drug that fixes my bald spot, shrinks my prostate, and helps prevent prostate cancer, for which I have a family history. It seemed like a win-win situation, a no-brainer!
Bottom line: Prostate cancer is very prevalent in men, involving one in six men in the USA. When picked up on a timely basis via screening with the digital rectal exam and blood PSA test, it is eminently treatable and has an excellent prognosis, with only 3% of deaths in the USA attributable to prostate cancer. There are both genetic and environmental factors at work in the genesis of prostate cancer. We are not in control of our genetics, but we are in command of our lifestyle. Maintaining a healthy lifestyle—including rational food choices—can help mitigate our chances of developing prostate cancer.
Andrew Siegel, M.D.
September 30, 2011
For more information on prostate cancer:
American Cancer Society: http://www.cancer.org
American Urological Association Foundation: http://www.auafoundation.org
Cancer Care: http://www.cancercare.org
National Cancer Institute: http://www.cancer.gov
National Prostate Cancer Coalition: http://www.pcacoalition.org
Prostate Cancer Foundation: http://www.prostatecancerfoundation.org
Prostate Cancer Research and Education Foundation: http://www.pcref.org
Us TOO Prostate Cancer Education and Support Network: http://www.ustoo.org