Three recent reports challenging the usefulness of prostate-specific-antigen screening have sent a reminder that prostate cancer demands a cool head.
The first, in May, by the U.S. Preventive Services Task Force. gave PSA tests a D grade on a scale that rises to A and recommended healthy men stop taking them. No patient representatives, urologists or oncologists participated in the decision, but the recommendation paralleled the practice of the United Kingdom’s Health Service, which has rejected routine PSA screening as imprecise and likely to yield overtreatment.
The second, in July, by the American Society of Clinical Oncology, recommended that doctors discuss PSA tests with men expected to live another 10 or more years, but discourage them for men with life expectancies less than 10 years.
The third, also in July, the Prostate Cancer Intervention Versus Observation Trial, supported by three bodies including the Veterans Administration and the National Cancer Institute, focused on radical prostatectomy surgery in men already diagnosed and concluded this surgery does not appear to save lives as compared to "active surveillance." The results underlined the same concern behind criticism of PSA screening: overtreatment. By implication, if the operation confers little benefit, the same may be true of the screening.
The task force, a 28-year-old, 16-member independent but government-agency-supported committee that reviews statistics bearing on primary care and prevention, relied on two studies. A large one in the U.S. with up to 13 years follow-up suggested screened men die of prostate cancer as often and as soon as men not screened. A larger one in Europe followed men for up to 11 years and found a survival benefit to screening. The task force concluded the benefits of screening were outweighed by a greater likelihood of incontinence and/or erectile difficulties in men pushed to treatment by their PSA results. It also noted rarer health problems linked to treatment or biopsies. The number of men benefiting from screening was small, it concluded.
The Annals of Internal Medicine, which published the task force's report, also published a rejoinder by urologists pointing out flaws in the studies favored by the task force. They said: (1) the American study failed as a true screening trial because data was contaminated by widespread departures from protocol; (2) the task force downplayed a Swedish study indicating a 44 percent benefit from PSA screening over a 14-year follow-up; and, (3) it undervalued American data showing a 40 percent reduction in prostate cancer deaths after the introduction of PSA testing in the early 1990s and a 75 percent drop in patients with advanced disease on their first visit.
These urologists added that the European study found a 21 percent reduction in deaths among those screened compared to the control group, a 29 percent reduction after adjustment of figures for non-compliance with protocol, and a 31 percent reduction in deaths among those screened after further adjustment for compliance lapses at one study site. The task force, they argued, overlooked that complications also afflict unscreened men and at a later stage in the development of their cancers, and noted that control group participants in the European study showed more high-grade cancers.
A study with a 10-year follow-up, they added, should not be grounds to tell a man 50 or 60 years old with a chance to live 30 or 40 more years how to handle prostate cancer. Thus the task force underestimated the benefits and overestimated the harms of PSA testing, these urologists said.
The ASCO recommendation came as a new entry in the group’s practice guidelines about two months after the ASCO Post newsletter reported the European study showed "a significant 21 percent" reduction in the risk of death for screened men 55-69 at the start of the study.
The PIVOT study followed only 731 men; thus, The New England Journal of Medicine, which published it, editorialized that the study was too small to provide definitive conclusions. The study followed men for 15 years and considered only one available treatment, radical prostatectomy. This operation, the study indicated, does not save lives for men with early stage cancer but does make a difference for men with PSA levels above 10 ng/ml.
The vulnerability of the data and continuing disagreement in the field did not stop the task force from making a well-intentioned judgment call that all men needed to be protected from PSA tests. But judgment calls in this matter should be left to individual men, at least in the manner suggested by ASCO.
A clue to one’s prostate-cancer status is available via a PSA test plus a digital rectal exam and a follow-up biopsy if needed. Without a clue, discovery may come too late except for those with shorter life expectancies and slow cancers. Nothing should interfere with a man’s access to a PSA test if he wants one, and efforts to find a better test should continue.
Many men already avoid PSA screening. Doctors may continue their current approaches. Little may change. Testing of men over 74 did not decline after the task force recommended against that in 2008. But the task force’s recommendation might prompt Medicare, Medicaid or private insurers to reevaluate their support.
After a certain age, this disorder is normal, if sometimes deadly. International studies estimate about 80 percent of men have at least an indolent form by the time they are 80.
Most men will not lose their heads at a rising PSA score and then act to hurt themselves if not shielded. Suggestions to the contrary introduce an element of patronization. Let men decide for themselves whether to have the test, working from information and counseling provided by doctors and others that know the disorder.