For years, physicians and their patients have decided, on an individual basis, whether or not to use a prostate-specific antigen (PSA) screening test, which can detect not only life-threatening prostate cancer but also many cancers that may never pose a danger. No clear evidence exists for whether the test provides more benefit or harm, given the aggressive treatments that often follow a positive cancer diagnosis, and so patients and physicians face a difficult choice about whether to use the test. Without definitive data, the U.S. Preventive Services Task Force (USPSTF), part of the federal Agency for Healthcare Research and Quality, issued guidelines in 1996 and again in 2002 that said it cannot recommend for or against PSA testing. Many other organizations that provide guidance to physicians ordering PSA tests—such as the American Cancer Society, the American College of Physicians, and the American Academy of Family Physicians (AAFP)—also adopted this position. Despite the lack of evidence, the PSA test became popular, especially for older men. In 2006, more than 58% of men aged 50–59 years had a PSA test within the past 2 years, according to prevalence data compiled by the U.S. Centers for Disease Control and Prevention. Older men used the test much more often. The Centers for Disease Control reported that 72% of men aged 60–64 years had had a PSA test, and for men aged 65 years and older, it was almost 77%. PSA testing has also led to unprecedented rates of treatment for prostate cancer: More than 90% of men diagnosed with the disease receive some form of treatment, even though many researchers believe that most prostate cancer cases will never become a health issue. Only about one-sixth of patients diagnosed with prostate cancer ultimately succumb to the disease, but there is no way currently to identify which prostate cancers should be treated aggressively. Now, citing new findings, the USPSTF has recommended that men aged 75 years and older not be screened with the PSA test, and it reiterates that the benefits of the test are still unproven in younger ages. The USPSTF laid out its recommendations in the August 5 issue of the Annals of Internal Medicine, saying that men who have a life expectancy of 10 or fewer years would suffer more immediate harm than long-term benefit from the consequences of a PSA screening test. U.S. population figures show that most men don't live beyond age 85. About 71% of deaths from prostate cancer occurred in men older than 75 years. And because dying from prostate cancer once it is diagnosed often takes at least a decade, men this age will probably die from other causes before the cancer kills them. Therefore, task force members say age 75 years should be the cutoff for prostate cancer screening. But some physicians predict that the USPSTF's revised guideline will generally be ignored—particularly by urologists—for a variety of reasons, including fears of age discrimination, ingrained medical practice, and health care economics. The new guidelines are “understandable and reasonable” when one considers that there are no randomized clinical trials that have yet demonstrated a mortality benefit to men who were screened with PSA or digital rectal exams at any age, said Peter Scardino, M.D., chairman of the department of surgery at Memorial Sloan-Kettering Cancer Center. “From a public health point of view, screening has not been proven. But what makes sense in theory may not in practice,” Scardino said. “If an older man comes in and says he wants a PSA test, I think any doctor will agree to it.” “The USPSTF guidelines, for the most part, have been received with indifference by the clinical community, in my opinion,” said David Penson, M.D., a urologist at the University of Southern California. Establishing an age-specific cutoff time is “arbitrary and unfair and might deny men a potentially beneficial intervention,” he said. In any case, “the proverbial cat is out of the bag,” Penson said. “One of the biggest issues that clinicians face is that patients demand prostate cancer screening, regardless of their age. It is difficult to convince patients otherwise, even if it is absolutely clear that they will not benefit from screening.”
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Apr 5, 2009
Camilla De Chermont Prochnik Estima + 4
Open Access