“How few things can be demonstrated! …Who has proved that tomorrow will dawn, and that we will die? And what is more widely believed!?” (Pascal’s Pensees)
Prostate cancer is a common cause of death and disability. It is the most common visceral cancer in men and the second-leading cause of cancer death. Death from prostate cancer is terrible—with pain, suffering, and disability for the patient and extreme distress for his loved ones.
There is no known means of preventing prostate cancer and no known cure for advanced-stage disease; therefore, the only method for reducing the mortality and morbidity from prostate cancer is to detect it early and treat it effectively.
Screening with prostate-specific antigen (PSA) can detect prostate cancer much earlier than it can be detected without screening. PSA screening has been widely performed during the past decade. Most tumors are detected while still confined within the gland, and metastatic disease at diagnosis has all but disappeared. Before PSA screening, it was a far different situation; most cancers had spread beyond the prostate, and treatment options were much more limited. Although the lead time provided by PSA screening varies, in most patients, screening provides a 5 to 10-year lead time in cancer detection. Coincident with widespread PSA screening have been advances in the method for performing prostate needle biopsies and improvements in surgery and radiotherapy.
During the past half decade, there has been a striking reduction of prostate cancer mortality rates in the United States and other countries. The decrease has been ascribed, at least in part, to early diagnosis combined with more effective treatment, although there is no proof of a causal relationship. Nevertheless, to the extent that early detection and effective treatment do reduce prostate cancer mortality and morbidity rates, PSA screening is clearly beneficial to many patients.
Some argue that PSA screening is not beneficial for all men screened because not every patient with prostate cancer benefits from early diagnosis and treatment. Some tumors might never be life threatening, and rare ones are incurable by the time the PSA level becomes elevated. However, all available evidence suggests that PSA screening largely detects cancers that have features of clinically important cancers while they are still curable.
Some also argue that PSA screening is not beneficial to men who are never affected by prostate cancer. PSA screening does provide a feeling of well being in men who have persistently normal results, and even though a normal value can be misleading, with serial screening, PSA eventually reveals the cancer.
Some have stated that PSA screening causes anxiety and starts the patient down a “slippery slope” fraught with risks of future side effects; therefore, PSA screening is potentially harmful. There is negligible pain associated with the blood draw, and the anxiety associated with having abnormal test results goes with any medical test.
Some emphasize that PSA testing is associated with a high false-positive rate. Although it is true that approximately 6% of all men screened and 60% with abnormal results have false-positive tests, both patients and physicians have come to grips with this, and they accept it.
The risks associated with the biopsy for abnormal screening results are minimal. With the advent of local anesthesia, the biopsy procedure is safe and not more unpleasant than a visit to the dentist.
Much debate has surrounded the risks associated with treatment of prostate cancer. There are risks, but this is cancer we are talking about, and with sound medical judgment, treatment selection can maximize potential benefits and minimize potential harms.
Some raise concerns about economic considerations. Although PSA screening, follow-up testing, and treatment have economic costs, in the long run, it is less costly to treat early prostate cancer than advanced-stage disease, and human lives are at stake in the balance.
Because of these issues, PSA screening has been controversial since its inception. There have been those who have questioned whether PSA screening does more harm than good. A balanced assessment of the evidence now overwhelmingly suggests that in appropriately selected men, PSA screening allows curative treatment of silent prostate cancers that otherwise would cause death and disability, and the benefits of PSA screening outweigh any potential harm. Therefore, early detection through PSA screening is indicated for men who are at risk of prostate cancer death. Granted that until there are reliable results from valid clinical trials, it will be difficult to prove that screening is beneficial. However, there is nothing new about the lack of proof in medicine. We lack formal proof from randomized clinical trials that avoiding smoking, getting regular exercise, and weight control are beneficial. The absence of proof of a benefit is not the same as the proof of the absence of a benefit.
The medical community has become polarized about PSA screening. Opponents take the societal perspective that screening should not be recommended until there is proof that it does more good than harm. Screening advocates take the perspective of the patient with prostate cancer that with no means of prevention and no cure for advanced-stage disease, the only practical strategy for avoiding death and disability is to detect it early and treat it effectively. This polarization is reflected in the different recommendations of medical organizations. For example, the American College of Physicians and the U.S. Preventive Services Task Force do not endorse PSA screening. On the other hand, the American Cancer Society and the American Urological Association recommend that men aged 50 years and older with at least 10 years of life expectancy should be offered PSA screening each year. High risk men such as African-American men and men with a strong family history of prostate cancer should be offered screening at an earlier age.
Panels of assembled experts hotly debate the language for screening guidelines. Should screening be “performed” or should it be “offered,” or should we just say there is insufficient evidence to make a recommendation? Is it appropriate to discourage screening? Should we require full informed consent before proceeding with screening? These seemingly subtle nuances can profoundly affect the access of men to PSA screening in clinical practice.
Physicians are generally expected to obtain informed consent for interventions that involve a risk of possible harm. The advantages and disadvantages of PSA testing should be explained to patients, but this does not need to take the form of a formal signed consent form. There are few “simple” tests in medicine for which formal informed consent is required. Consider cholesterol testing, breast examination, Papanicolaou smear, occult fecal blood testing, digital rectal examination, electrocardiography, and so forth. All these tests have a potential for a “slippery slope” of follow-up testing and treatment that could conceivably be more harmful than beneficial. Nevertheless, informed consent, like apple pie and motherhood, is hard to argue against because it ensures that patients are fully aware of what they are getting into when they have a medical procedure.
On the other hand, requiring a signed consent form before PSA testing could be harmful if it discouraged PSA testing, either because it was too time consuming or it presented the issues in an unbalanced way. An important drawback of informed consent is the time required to explain the controversy in the setting of a busy clinical practice. With most primary care physicians scheduling 15 to 30 minutes per patient visit, there is usually not enough time to provide informed consent properly for a PSA test and still deal with other important healthcare issues.
It would be more convenient for a physician to be able to check off a PSA test as a part of the routine laboratory testing without having to go through a formal consent process. Moreover, if informed consent for PSA testing were to be required, it would be desirable to provide the patient with information in advance, to expedite dealing with it during the office visit.
The way in which the issues are presented to the patient is of critical importance, and it is essential for the information to be not only balanced but also appropriately weighted. We should not hide behind the absence of a prospective clinical trial. However, experts would disagree and physicians would differ in the “spin” put on any material presented to the patient. It has been shown that some men given informed consent choose not to have PSA screening when told about the absence of clear evidence regarding the benefit of screening and evidence that some men treated as a result of a positive test have side effects.
It is important that a requirement for formal informed consent not be used as an instrument to discourage or provide an obstacle to PSA screening. All men who could benefit from PSA screening should not only be offered it but should be encouraged to have it, and men who ask for PSA screening should not be discouraged from having it, or worse, denied it.
Of course, we should explain all issues to our patients and answer their questions. It is our duty to advise our patients to the best of our knowledge. Usually, we must do this with incomplete information and lacking positive proofs.
PSA is here to stay—doctors and patients will have their PSA screening—and in appropriately selected men, PSA screening will prevent suffering and save lives. You can be as certain of that as of tomorrow’s dawning!
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