National Center for Health Research’s Comments on
the U.S. Preventive Services Task Force’s Draft Recommendation Statement
on Prostate Cancer Screening
Thank you for the opportunity to express our views on the draft recommendations for prostate cancer screening.
The National Center for Health Research is a nonprofit think tank that conducts, analyzes, and scrutinizes research, policies, and programs on a range of issues related to health and safety. We do not accept funding from companies that make products that are the subject of our work.
We support the efforts of the U.S. Preventive Services Task Force (USPSTF) to re-evaluate its recommendations in light of new research regarding prostate cancer screening that provides new insights into its benefits and risks. The issue of screening for prostate cancer is complex, because the benefits and risks vary in unknown ways for individuals. For a subset of men, the benefits may outweigh the risks, but for others the situation is reversed. Therefore, a recommendation that, for men aged 55-69 years, the decision is best determined by a patient and their doctor with a rating of “C” may be warranted. However, we have strong concerns about the basis for this change in recommendations and its likely impact on screening. We agree with the USPSTF that the risks outweigh benefits for men who are 70 years old and older.
Changing the grade and recommendation for men aged 55-69 from a “D” to a “C” and from “risks outweigh benefits” to “talk with your doctor” may make patients and practitioners believe that the data supporting screening is now stronger than it was previous. Unfortunately, most doctors have neither the time nor the communication skills to do convey the ambiguities of risks and benefits to their patients. As a result, the proposed change would be likely to increase screening for most men.
When the USPSTF changes a recommendation, the scientific data should strongly support that change. It should indicate a difference in overall survival, not just a change in deaths from the specific disease being screened.
The review lists the benefits of screening for men 55-69 years as preventing 1.3 death from prostate cancer and 3 cases of metastatic prostate cancer for every 1,000 men screened over a 13-year period. The data supporting the 2012 “D” recommendation predicted that screening would prevent 0.7 deaths per 1000 men screened and did not include information about metastatic cancer. This is a small increase, but more importantly, prostate cancer screening has not been shown to improve overall survival. Experts agree that the vast majority of men with prostate cancer will die with prostate cancer, rather than die of prostate cancer. Instead, the vast majority will die of another cause. And yet, the complications of prostate cancer treatment often substantially harm quality of life. Out of these same 1,000 men, 273 would have a positive PSA test, and 35 would get a cancer diagnosis. If these 35 men were treated with radical prostatectomy, 24 would not benefit from treatment, 7 would have long-term erectile dysfunction, and 2 would have long-term problems with urinary incontinence requiring a diaper.
The data on quality of life are definitely confusing. While the surgical patients have the worst adverse events – primarily erectile dysfunction and incontinence, they tend to score well on general quality of life. In contrast, the radiation patients are less likely to have these adverse events, but more likely to score poorly on various quality of life measures. Hormone therapy tends to have negative impact on adverse reactions and on general quality of life.
It seems clear that the general quality of life measures that were used in these studies are not measuring quality of life related to the adverse events that are assumed to be most severe – erectile dysfunction and incontinence – but in the case of radiation and hormone treatment, are measuring some significant problems. And, perhaps active surveillance is also taking a toll on quality of life, because the knowledge that a man has prostate cancer has a negative impact when he doesn’t treat it.
Looking dispassionately at these numbers, it seems clear that patients’ decisions regarding treatment for prostate cancer should be carefully discussed with one’s doctor. But the question here is screening, not treatment. The data clearly indicate that screening is having a negative impact, because once a man has a high PSA and is found to have prostate cancer, he seems likely to feel worse than he felt before screening whether he seeks treatment or active surveillance. Given that there is no evidence that any of these treatments improve overall survival, how can one justify recommending prostate screening for men with no symptoms? If the USPSTF believes that it is important to reduce overtreatment and unnecessary harm, data on overall survival is crucial to determine if screening should or should not be recommended.
Even when screening tests accurately detect cancer, they cannot accurately predict whether a tumor will become life threatening within the man’s lifetime. There is a high rate of overdiagnosis and subsequent overtreatment. Longer-term studies and studies designed to distinguish between higher and lower risk populations (for unproblematic vs. concerning cancers) may help address these issues in the future. However, these data will not help men and their doctors with the issue now. On the other hand, the use of active surveillance as opposed to other treatments could help reduce harms, but only if it is considered a real option by doctors and patients.
If men decide to undergo screening for prostate cancer, it is important that they are educated about the risks and benefits of specific screening tests. Prostate-specific antigen (PSA) tests have a high rate of false positives, between 20% and 50%. This leads to unnecessary stress and anxiety, as well as increased follow-up testing. The PSA test alone is insufficient for diagnosis because it also detects other changes in the prostate and even urinary tract infections, making follow-up tests are necessary. One of the most common follow-up test is a biopsy, which has its own risks, including injury requiring hospitalization.
Changing the grade and recommendation for men 55-69 years of age testing from a “D” to a “C” and from “risks outweigh benefits” to “talk with doctor” will likely increase the use of screening. If done properly, this may help a small number of men. However, if discussions between doctors and patients are not effective at sharing information to help patients weight the risks, benefits, and the patient’s personal values, then there will be an increase in overdiagnosis, overtreatment, and medical complications.
For questions or more information, please contact Stephanie Fox-Rawlings at email@example.com.
Draft Recommendation Statement: Prostate Cancer: Screening. U.S. Preventive Services Task Force. April 2017.
Draft Evidence Review: Prostate Cancer: Screening. U.S. Preventive Services Task Force. April 2017.
Final Recommendation Statement: Prostate Cancer: Screening. U.S. Preventive Services Task Force. May 2012.
Lin K, Croswell JM, Koenig H, et al. Prostate-Specific Antigen-Based Screening for Prostate Cancer: An Evidence Update for the U.S. Preventive Services Task Force [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2011 Oct. (Evidence Syntheses, No. 90.) https://www.ncbi.nlm.nih.gov/books/NBK82303/