Last week, the U.S. Preventive Services Task Force finalized a blanket recommendation that all routine prostate specific antigen (PSA)-based screening for prostate cancer be stopped in this country. The new guideline won swift praise in some quarters and strong condemnation in others -- leaving men and those who love them wondering what to do.
Elements of truth exist on both sides: Since the advent of PSA screening in the U.S., national prostate cancer mortality rates have fallen steadily and are now about 40 percent lower than they were 15 years ago. The proportion of this decline attributable to screening remains controversial, but there is little question that many thousands of men owe their lives to PSA testing.
However, it is axiomatic of prostate cancer that most men are much more likely to die with it than from it. If a man lives long enough, it is a virtual certainty that his prostate will eventually develop abnormal cellular growth which, under the microscope, has some of the hallmarks of malignancy. Up to 35-50 percent of men in their 50s and up to 80 percent of men in their 70s have microscopic prostate cancer. Many of these grow so slowly -- if ever -- that they likely do not even deserve the moniker "cancer."
Many men have undergone treatment, most often surgery and radiation, for these indolent prostate tumors that never would have caused them any symptoms or loss of life had they never been diagnosed. Some suffered needlessly from long-term incontinence, impotence, or other debilitating side effects.
A subset of prostate cancers, however, progress rapidly and aggressively, ultimately killing more men than any tumor except lung cancer. Thus, it is important to identify those men who may benefit from treatment.
The oft-repeated statement that one cannot reasonably distinguish the indolent prostate cancers from the aggressive ones is a myth. With basic information available on all patients in contemporary practice, prostate cancers can be risk-stratified with a good degree of accuracy. With the advent of novel blood, tissue, and imaging tests, predictive accuracy will increase further in the very near future.
The serum PSA test should not be used alone for screening; it leads to too many unnecessary biopsies. A better estimate of individual risk, including the risk of more lethal disease, can be obtained by combining the PSA test with other information such as age, family history, ethnicity and a host of novel markers being incorporated into so-called risk calculators.
The problem is that treating clinicians have historically done a poor job matching the right patients with the right treatments. These trends are starting to change, and a key advance in recent years, championed by many (including us and others at our institution), is active surveillance for men with low-risk prostate cancer.
Some writers (including the USPSTF) incorrectly conflate active surveillance with the older concept of "watchful waiting," which implies doing nothing, in effect sitting under a sword of Damocles and nervously fearing that the disease may progress to an incurable state. Active surveillance, in contrast, entails careful observation of the tumor through serial testing, with every intent of cure at the first sign of progression. To embrace active surveillance is to descend from the horns of the dilemma between avoidable overtreatment and anxious passivity in the face of an unnerving cancer diagnosis.
In addition to active surveillance, the vast majority of men who are found to have indolent prostate cancer should be encouraged to make comprehensive lifestyle changes, including nutrition, exercise, stress management and social support. This approach empowers and actively involves patients in their health rather than passively "watchfully waiting" for something bad to occur.
Such lifestyle changes may reverse even severe coronary heart disease (the No. 1 killer of men with prostate cancer, as it is for men without prostate cancer). These changes may suppress genes that promote prostate cancer, and additional evidence suggests that they may also slow or stop the progression of early-stage prostate cancer.
Indiscriminate screening of men with limited life expectancy and overtreatment of men with low-risk prostate cancer cause significant harm, waste vast resources, and are clearly not in the interests of the nation's public health. But to stop all PSA screening, as the USPSTF has advocated, would be to condemn thousands to slow, painful, and entirely avoidable deaths.
The solution then, is neither to screen all nor to screen none, but rather to screen smarter -- to focus screening efforts on men in good health, at younger ages, and less frequently for most men -- and to treat better, reserving surgery and radiation for men with aggressive disease most likely to benefit, and encouraging lifestyle changes and active surveillance for the larger number of men with indolent prostate cancer.
Matthew R. Cooperberg, M.D., M.P.H.
Assistant Professor of Urology
University of California, San Francisco
Dean Ornish, M.D.
Founder & President
Preventive Medicine Research Institute
Clinical Professor of Medicine
University of California, San Francisco
www.ornish.com
Peter R. Carroll, M.D., M.P.H.
Professor and Chair, Department of Urology
University of California, San Francisco
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