Prostate screening and disease

By | 26 Augustus 2009

If I have an  abnormal clinical finding, does that make me a patient?


Many  (especially older)  people are regularly reminded  by their doctor that it is time for an annual check-up.  They usually feel  reasonably well, but modern medicine,  with its preoccupation with figures and statistics, does not usually allow this euphoria.

Usually they will be told that they have hypertension or diabetes or high cholesterol  or even that they are obese or exercise too little or have unhealthy eating habits or that they drink too much. In the British National Health System general practitioners are rewarded according to “The Quality and outcomes” framework (QoF) where good performance earns awards points on the system, with related payments for each documentation. Many patients are sent for more tests and eventually most are started on pills. Few are considered not at risk for something.

Thus, of those who thought themselves as healthy, a number will return home as patients  and even be worried by the perception that they are now regarded to be ill.  What kind of medical system  is this:  turning people into patients?

It seems that many governments see 75year olds as patients. It is a trend with many causes, including overenthusiastic and uncritical interpretation of various guidelines, the payment structure of the NHS obsession with government targets superceding common sense, insurance companies and relentless pressure from drug industry.

Many busy family doctors do not understand the difference between relative and absolute risk. If an advantage has been shown of one treatment over the other of say 30%,  but you had to enroll 100,000 patients to get nine patients to improve versus six in the no treatment group, the absolute risk is negligible and the treatment should not be implemented.

I would like to use prostate examination for detection of cancer as an example.  There are two risks to screening for prostate cancer. It depends on your view where you would see the greatest risk  –  it can be in either:

1)       Not to screen, and miss a cancer

2)      Overdiagnosis and overtreatment, with dire consequences.

The following discussion becomes quite technical and younger readers might find it heavy going (feel free to skip this), but the adult men I see in my practice always have questions about possible prostate pathology.

“Overdiagnosis”  refers to the detection,  by screening,  of conditions that would not have become clinically significant (you cannot prevent something that would not have happened anyway).  It may thus happen, by screening, that cancer, that would never have become clinically significant, is found.  Patients are subject to the risks of screening, confirmatory diagnosis, and treatment, as well as suffering potential psychosocial harm from anxiety and labeling. “Overdiagnosis”  is of particular concern because most men with screening-detected prostate cancers have early-stage disease and will be offered aggressive treatment with potential long term consequences.

A number of reports have raised concerns about the risk of overdiagnosis through screening: While the lifetime risk of being  DIAGNOSED  with prostate cancer is now 1 in 6, the lifetime risk of DYING  from prostate cancer is only 1 in 34 [1] . Although about 80 percent of detected cancers are considered clinically important based on tumor size and grade [129] , these are relatively crude prognostic markers. An autopsy series in men who died from other causes have shown a 30 to 45 percent prevalence of prostate cancer in men in their fifties and an 80 percent prevalence in men in their seventies [130-132].  (This means that almost all men will in the long run develop prostate cancer if they live long enough).

A study that applied computer-simulation models of PSA testing to cancer incidence data estimated that 29 %  of cancers detected in whites and 44 % of cancers detected in blacks were overdiagnosed [133] . Similarly, a study that applied simulation models to the results of the European Randomized Study of Screening for Prostate Cancer estimated a 50 % overdetection rate with annual screening for men aged 55 to 67 [13] .

What are the risks of  therapy?

Even in the absence of treatment, many men diagnosed with prostate cancer as a result of screening will have a lengthy period of time without clinical problems. However, undergoing radical prostatectomy and radiation therapies can lead to immediate complications: The operative mortality rate is about 0.5 %  [134] (1 %  in men over 75 years of age)  [135] . Less serious, but more common, complications include urinary incontinence, sexual dysfunction, and bowel problems. Radical prostatectomy can substantially decrease sexual function in 20 – 70 % of men and lead to urinary problems in 15 – 50 %  [136,137] .

External beam radiation therapy has been reported to cause erectile dysfunction in 20 – 45 %  of men with previously normal erectile function, urinary incontinence in 2 – 16 % of previously

continent men, and bowel dysfunction in 6 – 25 %  of men with previously normal bowel function [136,138] .

Given the lack of data on whether screening improves disease-free survival, the quality of life issues related to treatment selection become increasingly important decision-making factors.

The American College of Physicians provided a useful summary of discussion points to consider when counseling patients about prostate cancer screening [140] :

Prostate cancer is an important health problem.

The benefits of one-time or repeated screening and aggressive treatment of prostate cancer have not yet been proven.

Digital rectal examinations and PSA measurements can have both false-positive and false-negative results.

The probability that further invasive evaluation will be required as a result of testing is relatively high.

Aggressive therapy is necessary to realize any benefit from the discovery of a tumor.

A small but finite risk for early death and a significant risk for chronic illness, particularly with regard to sexual and urinary function, are associated with these treatments.

Early detection may save lives.

Early detection and treatment may avert future cancer-related illness.

A healthy lifestyle does play a role:  low fat diet, exercise, no smoking, avoid chemical carcinogens is always protective in a large number of diseases.

Physicians find it challenging to provide comprehensive, consistent, and balanced information about prostate cancer screening decisions during clinic visits [144] . Consequently, efforts have focused on using decision aids to help patients understand screening issues and make informed decisions for screening [145] .

Investigators have evaluated a number of interventions to facilitate such informed prostate cancer screening decisions including videotapes [146-148] , patient group discussions [146] , brief scripts read to patients during clinic visits [149] , verbal and written material provided before a periodic health examination [150] , and informational pamphlets distributed at study visits [151] or through the mail [152] .

Before full information 98% of men reported for  PSA screening,  but with complete information only 50% of men reported for screening.

This means the (informed) choice is yours.  Your decision will depend on what is important in your life.  Family history of early cancer?  How important is your virility to you? Fear of illness or death?

RECOMMENDATIONS FOR SCREENING BY EXPERT GROUPS — In the face of the lack of outcomes data from randomized, controlled trials, major medical associations and societies have not come to a clear consensus regarding recommendations for screening for prostate cancer.

1.The United States Preventive Services Task Force (USPSTF) concluded that there is insufficient evidence to assess the balance of benefits and harms of prostate cancer screening in men younger than age 75 . The USPSTF recommends against screening for prostate cancer in men ages 75 or older because the harms of screening outweigh the benefits.

2. The Canadian Task Force on Preventive Health Care recommends against screening for prostate cancer with PSA and states that there is insufficient evidence to recommend for or against screening with DRE (digital rectal examination)] .

3.A number of European groups, including the European Union,  recommend against screening for prostate cancer while awaiting the results of randomized trials .

4.The American Cancer Society (ACS) emphasizes the need for physicians to provide men with adequate information regarding the risks and benefits of screening  . The ACS recommends that serum PSA testing and DRE should be offered annually to men 50 years of age and older who have a life expectancy of 10 years. The guidelines also stress the benefit of screening beginning at age 45 in patients at high risk of developing prostate cancer (eg, black men and men with a first-degree relative with prostate cancer diagnosed at a younger age). PSA testing is recommended for men who ask their clinicians to make the decision about screening on their behalf. The American Urological Association (AUA) also supports this policy .

5. The American College of Physicians (ACP) recommendation states that “Rather than screening all men for prostate cancer as a matter of routine, physicians should describe the potential benefits and known harms of screening, diagnosis, and treatment; listen to the patient’s concerns; and then individualize the decision to screen” . The ACP also suggests that men between the ages of 50 to 69 years are most likely to benefit from screening. Black men and men with a positive family history of prostate cancer should be informed of their higher lifetime risk, although the available evidence does not suggest that they need to be treated differently from men at average risk.

Two new studies into prostate-specific  antigen (PSA) screening for prostate cancer published in the NEJM have raised more questions than they answered.

  1. One study found that the test had virtually no impact on prostate cancer and only lead to high risk of overdiagnosis and overtreatment.
  2. The other study, on the other hand,  showed a small reduction in mortality risk after a nine year follow-up  in men who were screened regularly with PSA.  The study published in NEJM 18 March from American Cancer Institute and European Erasmus Centre looked at 182,000 men in Europe and 77,000 men in the US.  According to the US investigators mortality was actually somewhat higher in the screened group..

Daar is nog twyfel oor die vraag of ons sekere pasiente kan vrywaar daarteen om prostaatkanker te ontwikkel.  Deur jaarliks vir prostaat ondersoeke te gaan glo ons dat dit bydra tot gesonde lewenstyl. Baie van ons gaan getrou elke jaar vir hierdie ondersoek (waaraan  baie min mans hulleself  vrywillig aan sal onderwerp.

Om nou te hoor dat ons nog steeds nie die sekerheid van wetenskaplike bewyse het dat  die ondersoek wel  lewens  spaar en ons nie net teen prostaatkanker beskerm nie maar ook lewens  sal red,  onstel baie van ons.   Wat is die feite,  moet ons maar die ongemak een maal per jaar verdra, of is dit nie bewys om lewens te red nie?

Om hierdie vraag te probeer antwoord het  navorsers by een van die beste kanker- eenhede in die wêreld,  nl. die “Division of Cancer Prevention, National Cancer Institute” in Bethesda in dieVSA, ‘n navorsingsmodel opgestel.  Tussen 1993-2001 het hulle op lukraak wyse 76,693 mans in twee groepe verdeel.

  1. Een groep van 38,350 mans kry ‘n jaarlikse rektale ondersoek en ‘n PSA- bloedtoets, volgens ‘n streng protokol.  Die PSA word vir 6 jaar opgevolg en die rektale ondersoek vir 4 jaar.
  2. Die ander 38,350 mans kry gewone ondersoeke,  wat beteken nie noodwendig rektale en PSA-ondersoeke nie,  maar soms wel indien die dokter dit nodig sou ag.

Resultaat:  In die toetsgroep word 85% ondersoek en die kontrole groep word 52% ondersoek. Na 7 jaar waarin die groepe opgevolg word is die insidensie van prostaat kanker per  10,000 persoon jare 116 (2820 ware gevalle) in die proefgroep, en in die kontrole groep 95 (2322). Die sterfgevalle in die toets groep was 2 (50)per 10,000 persoon jare en 1.7 (44 )per 10,000 persoon jare. Dit het dus ‘n baie lae insidensie van sterfte getoon in albei groepe. Daar was geen verskil in die voorkoms van kanker of hulle ondersoek is of nie.

Uiteindelike vraag:  Is dit vir my die regte ding is om ondersoek te word?.  Waar lê die keuse tussen

  • oordiagnose en onnodige radikale behandeling;
  • of die kans dat ons ‘n kanker wat my kan doodmaak,  mis en die vroeё kans om genees te word misloop.

5 thoughts on “Prostate screening and disease

  1. leesmith18

    When I have cause to worry about a potentially life threatening disease, I have always sought out expert advice, as well as looking at publications in the area from experts. Hence, I would recommend you include the recent reports and recommendations form AUA and NCCN in your reviews. Both groups of experts in prostate cancer have recently presented updated recommendations which at least in my opinion are more meaningful than the groups you (and others) typically quote. Certainly as a patient, I would seek an expert in the area of prostate cancer and they populate the two above groups. There are also a number of critical comments about the recent published results including contamination of the studies by unanticipated PSA testing, etc, as well as out of date protocols.

    1. docfrancois

      To Mr R Lee Smith:

      Prostate cancer screening

      Thank you for your very relevant comments, and I agree that men need all the information they can get on this common condition. It also highlights the problem we have in an era of information overload, where even expert opinions differ. What to believe? You will also understand that the information I give on my blog is aimed at making people aware of health problems and the often differing viewpoints regarding treatment. Many people will shop around on the internet till they find an opinion that suits their own viewpoint. As in the financial world, the opinion you get will depend on which expert you ask. A blog is also not a complete scientific handbook.
      I have read quite widely on the subject, and the information was obtained from the latest medical journals. I also deal with this problem a lot in my medical practice as a specialist physician where I see many middle-aged and elderly patients, and work closely with our two resident urologists.
      What you say is true in the sense that men can die of prostate cancer, but we must remember men never die of prostate cancer in the early phases. I referred to the massive incidence of prostate cancer occuring in the general population, and that we do not know which patients are going to die from it. There are ten levels of malignancy, and that means that many operations and examinations are done to prevent cancer spreading in patients where it may not have progressed anyway. In certain patients that question is easily answered, but in the majority it is impossible.
      If you search under the webpage of the AUA (American urological society) Jeff Evans (senior writer) stated: The potential harm associated with prostate cancer screening in asymptomatic men older than 75 yr outweigh any potential benefit from cancer treatment according to the newest recommendations issued by the US Preventative service task force (Int med news 1 Sept 2008 vol 41 issue 17 p 20 ). We do not know where the grey area stops and no one can give that answer, and that is one of the points I discussed.
      The National Cancer institute also does not support widespread screening for prostate cancer. We had the same scenario in the nineties with the most common killer in men, viz. lung cancer – No1 on the list of deadly cancers. To detect lung cancer should be easy and then this most malignant and prevalent killer can be taken out at the first shadow on the X-ray, and the patient walks away cured. So we started to X-ray screen men and did sputum microscopy for cancer cells. The screening was stopped because not all shadows are cancers and not all abnormal sputum’s have sinister implications. The amount of unnecessary suffering and unnecessary operations made screening a dangerous exercise, let alone the expense. What initially seems plausible does not always turn out to be a good idea.
      I cited the New England Journal of Medicine of two months ago as well as the publication of Bethesda in Maryland, one of the most prestigious cancer institutes in the world. The “Up To Date” publication that I cited was published in June 2009.
      May I give advice in a very difficult and perplexing world of medicine. If you listen to experts in a very narrow field you get opinions of prostatologists – super super specialists. They earn their living from operations on prostates. In a hospital in Britain where a friend of mine worked the urologists were the only specialists who visited the hospital in their private helicopers.
      General advice is “ Treat the patient not the prostate.”
      What all this means is that the ball is in your court. You decide. BUT you must have the right information and the freedom to call the shots.

  2. leesmith18

    How do we try to understand the world around us. We can look at massive statistical studies and certainly they provide us with guidance but we can also seek to find the best case course through whatever problems seem to face us. In the end of course we all end up in the grave. When it comes to medical problems we have to deal with a set of professionals known as doctors and are continually faced with issues of trust. So what I do is try to balance what I see via mass statistics, what I learn from physicians who seem to be sincerely devoted to their patients and knowledgable and up to date and skilled in the practice of medicine. And then I look around at folks I know who have faced similar challenges. When it comes to prostate cancer I can only conclude based on all of this that I simply have little or no use for the USPSTF (did I get that right?) or the recently published NEJM articles which have been widely criticized in ways that I find quite meaningful. Your column on the other hand seems to take what these sources conclude as gospel while ignoring the sources I mentioned because of your experience with urologists with helicopters. So be it. We are playing by the same rules, ultimately our own experience from a limited number of cases. I will vote with they engineers and scientists in my university (I would bet more than the number of urologists with helicoptors) and community who have unfortunately ended up with fairly aggressive prostate cancer, diagnosed via PSA and biopsy, and generally chosing aggressive treatment in order to live out their lives as happily as possible. Certainly I agree with your final conclusion, but not getting routine PSA tests says to me that you are trying to play ball with one hand tied behind your back and will simply not be able to call any credible shots.

  3. leesmith18

    If you allow me some further comments, I realize now we are talking apples and oranges. From the point of view of those negative re PSA testing we are not individuals, but rather statistical occurrences. Unfortunately given present knowledge and ignorance about prostate cancer the statistics show that a number of men get unnecessary overtreatment. One way to eliminate unnecessary overtreatment is to not treat men. Of course that also will eliminate necessary treatment, but the statisticians can’t be concerned about that. As individuals however, we need to take a different approach. We need to figure out how to get necessary treatment while avoiding unnecessary overtreatment. Here is where our individual value systems also come into play in a way that the statisticians cannot deal with it. Each of us needs to evaluate a multiplication namely, the value we place on the chances of missing a diagnosis multipled by the negative cost to us of having to fight an agressive prostate cancer for the rest of our lives. The statisticians say too bad you have to take that chance. We say, no, I can optimize my situation by finding good doctors, getting good opinions, etc. Let’s assume most Drs are not particularly good then our odds of succeeding are poor. But each of us like to think we can find the right professionals to help us chart a course, in which case it seems unescapable to me that we need all the data we can get beginning with our PSA readings in order to maximize our life experience.

    1. docfrancois

      A good doctor will know that he does not know the future. He will also be able to give the information and statistics pertaining to you as individual with your specific aspirations and expectations to find a treatment you understand and are able to partake in making the decision.


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