Prostate Cancer Screening: Harms, Benefits, and Uncertainty

Prostate cancer is common, but our best way of screening men with the prostate specific antigen (PSA) test is not very accurate. This means that many men who did not need to be treated for prostate cancer are treated and experience the potential for negative side effects or harms from diagnosis and treatment. Evidence conflicts as to whether the PSA test for prostate cancer screening actually reduces the chance that a man will die of prostate cancer. One of the best explanations I’ve seen of the issues behind screening for prostate cancer with the PSA test is through this video from Dr. Mike Evans and Kaiser Permanente: www.youtube.com/watch?v=bTgS0DuhaUU. Dr. Evans discusses that “prostate cancer does not happen in one way and is not a rare event,” using the image of a turtle, rabbit, and bird to illustrate this point.

Organizations that have made recommendations about whether or not to use the PSA test to screen for prostate cancer looked at two major studies, one in America and one in Europe. The American study found no difference in men dying from prostate cancer between the group that regularly received a PSA test and the group that was not assigned to regularly receive a PSA test, called the usual care group.[i] The European study did find that less men died from prostate cancer after being a part of the group that had regular PSA tests, but this was a small reduction.[ii] In the study, about 1,000 men would have to be regularly screened for 10 years to save one man from dying from prostate cancer. The two studies have both been criticized, but for different reasons. In both there may not have been enough time that passed to see a large enough effect from the PSA testing. In the European trial the way that the PSA tests were done was very different between the eight different countries that participated and only two sites actually saw any benefit.  In the American study there was a high amount of PSA testing happening in the group that received usual care which may have caused the study to not find a significant result. Healthcare Triage does a good job walking through the statistics that large studies like these use in this video: www.youtube.com/watch?v=dHj7ygeqelw. For me, this is a good reminder that these are complicated issues and that the way that data is reported makes a big impact on what the data means.

The potential harms from PSA testing happen because of the consequences after a high PSA test: from the other tests that follow and from treatment.
– There can be stress and anxiety after a positive test.
– When a test comes back positive, there can be harms like infections from what is often the next step, a prostate biopsy.
– In those who have a positive biopsy, there can be harms from prostate cancer treatment.
– Common treatments involve surgery to remove the prostate and radiation which can result in serious complications such as heart attack, stroke, impotence, and urinary incontinence.[iii],[iv]

In May 2012, the United States Preventative Services Task Force, a volunteer group of national experts that makes recommendations about preventative services like screenings, released its recommendation “against prostate-specific antigen (PSA)-based screening for prostate cancer” giving the PSA test a D recommendation.[v] This means the task force came to the conclusion that “there is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits.” The Task Force created a consumer fact sheet that can be found here: www.uspreventiveservicestaskforce.org/Home/GetFile/1/11559/prostatecancerfact/pdf. The American Academy of Family Physicians also recommends against screening men for prostate cancer using the PSA test. Other guidelines including that of the American Cancer Society and American College of Physicians recommend that clinicians should have a discussion with all men starting at a particular age such as 50 or 55.

Most groups recommend that clinicians use a shared decision making process to talk with their patients. See more information about shared decision making and what our State is doing on our Bree Blog here: www.breecollaborative.org/2015/06/15/shared-decision-making/

Most men given the PSA test regardless of age are not informed of the harms, benefits, and conflicting evidence behind the test. If you are given a test, you deserve to know what a positive and what a negative result might mean and, as Dr. Evans says in his video, what this will trigger in our health care system. While the benefit of the PSA test is not clear, we encourage avoiding unwanted testing by allowing men to be informed of the harms, benefits, and conflicting evidence before being given a PSA test. All men should be evaluated by their provider for family history and factors that may elevate the risk of prostate cancer (e.g., first or second degree relative with a prostate or breast cancer diagnosis, race). We recommend against routine screening with PSA testing for average risk men 70 years and older, under 55 years old, who have significant co-morbid conditions, or with a life expectancy less than 10 years. Unfortunately, men over 70, 75, and even 80 are currently being screened.

The majority of our workgroup’s discussion involved whether to recommend clinicians bring up PSA testing for prostate cancer screening with all men, with men in a certain group, or with no men and allow men who are interested to bring up the topic with their clinicians. Our workgroup spent many hours talking about how the evidence from the two main studies conflicts and that there are limitations to both studies. We talked about the fact that PSA testing for prostate cancer screening can result in real harms and negative effects but that PSA testing may also have a possible beneficial impact on prostate cancer mortality.

We encourage clinicians to review existing evidence and we recommend two possible pathways depending on the clinician’s interpretation of the evidence.
– Clinicians who believe there is overall benefit from screening with PSA testing should order this test for average risk men between 55-69 years old only after a formal and documented shared decision-making process.
– Clinicians who believe there is overall harm from screening with PSA testing may initiate testing of average-risk men aged 55-69 at the request of the patient after a formal and documented shared decision-making process.
– The patient decision aids used in the shared decision-making process should be certified by Washington State when available.

Only men who express a definite preference for screening after discussing the advantages, disadvantages, and scientific uncertainty should be screened with prostate cancer with a PSA test. Right now our Prostate Cancer Screening Recommendations are out for public comment. Read our full Report here: www.breecollaborative.org/wp-content/uploads/Prostate-Cancer-Recommendations-Draft-15-09.pdf then take our survey and give your feedback: www.surveymonkey.com/r/JPM7839. Feedback must be received by 5pm on Friday, October 16th.

Ginny Weir, MPH
Bree Collaborative Program Director

[i] Andriole GL, Crawford ED, Grubb RL 3rd, Buys SS, Chia D, Church TR, et al. Prostate cancer screening in the randomized Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial: mortality results after 13 years of follow-up. J Natl Cancer Inst. 2012 Jan 18;104(2):125-32.
[ii] Schröder FH, Hugosson J, Roobol MJ, Tammela TL, Zappa M, Nelen V, et al. Screening and prostate cancer mortality: results of the European Randomised Study of Screening for Prostate Cancer (ERSPC) at 13 years of follow-up. Lancet. 2014 Dec 6;384(9959):2027-35.
[iii] Surveillance, Epidemiology, and End Results Program. SEER Stat Fact Sheets: Prostate Cancer. Available: http://seer.cancer.gov/statfacts/html/prost.html. Accessed: June 2015.
[iv]Potosky AL, Legler J, Albertsen PC, Stanford JL, Gilliland FD, Hamilton AS, Eley JW, Stephenson RA, Harlan LC. Health outcomes after prostatectomy or radiotherapy for prostate cancer: results from the Prostate Cancer Outcomes Study. J Natl Cancer Inst. 2000 Oct 4;92(19):1582-92.
[v] Moyer VA; U.S. Preventive Services Task Force. Screening for prostate cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2012 Jul 17;157(2):120-34.