When health policy makers are making decisions about PSA-based screening, first and foremost, they should bear in mind that the balance of harms and benefits cannot be determined given the current state of science and flawed methodology of the PLCO study. PCF thus calls for a step back from a grade D recommendation to an “I statement” with regard to PSA-based screening for men under the age of 75. Evidence is emerging that clinicians in primary care settings may misinterpret the D-grade recommendation as a sign of certainty that PSA-based screening is not warranted in any clinical setting, which could have the unintended consequence of missing lethal cancers that could have been detected early.
In 2017 the USPSTF issued an updated draft recommendation instead recommending shared decision-making about PSA screening, since the potential benefits and harms of prostate-specific antigen PSA-based screening are closely balanced in men ages 55 to 69 years, and therefore the decision should be an individual one. For men age 70 years and older, they continued to recommend against screening for prostate cancer, with the rationale that potential benefits do not outweigh the harms.
Who is the Task Force?
The U.S. Preventive Services Task Force (USPSTF) is an influential federal panel that identifies as an “independent, volunteer panel of national experts in prevention and evidence-based medicine.” The Task Force makes evidence-based recommendations with the stated objective to “improve the health of all Americans.” The USPSTF’s guidelines are referenced by clinicians, patients, and payers to make informed decisions about preventative services. It is worthwhile to note that the Task Force’s recommendations only apply to patients with “no signs or symptoms of the specific disease or condition under evaluation, and the recommendations address only services offered in the primary care setting or services referred by a primary care clinician.”
What is PCF’s Position on the USPSTF’s D-grade Recommendation Against PSA-Based Screening for Prostate Cancer?
In the Prostate Cancer Foundation’s opinion, there is an insufficient level of certainty to warrant a D-grade recommendation (meaning “there is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits”) against PSA-based screening for prostate cancer in all age groups. Given the current body of published and unpublished evidence on prostate cancer detection and screening, PCF calls for a replacement of the 2012 USPSTF designation of a D grade recommendation with an I statement for men under the age of 75 (meaning “evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined”).
The USPSTF solicited the Prostate Cancer Foundation’s expertise in 2012 and 2015 respectively and our published comments, which reflects input from multi-disciplinary experts in our scientific and medical community, appear below:
2011 PCF Comments to USPSTF on D-grade Recommendation Against PSA-based Screening | PCF calls for an “I statement”
2015 PCF Comments to USPSTF on Draft Research Plan | PCF Calls for the Task Force to consider incorporating emerging evidence on genomics-based tests in blood, urine, saliva and biopsy material and “smarter screening” approaches
2016 PCF Joins Coalition of Physicians and Patient Groups on Consensus Feedback to USPSTF Draft Research Plan | PCF joins Coalition of Physicians and Patients as USPSTF begins process of updating its recommendation on PSA-based screening for prostate cancer
What Emerging Evidence Underscores the Need to Reevaluate the D-grade Recommendation Against PSA-based Screening?
Unpublished data from the 2016 American Urological Association and 2016 American Society of Clinical Oncology meetings point to the increasing incidence in academic centers of locally advanced prostate cancers in men who were not screened with PSA tests. The risk of harm from overdiagnosis and overtreatment could be replaced by the greater risk of underdiagnosis and undertreatment of men who benefit from treatment. Tragically, this could lead to an increase in the death rate, thus reversing the dramatic reduction in prostate cancer deaths seen in the PSA era. The great astronomer Edwin Hubble once explained, “The scientist explains the world by successive approximations.” PCF believes that according available Level I evidence any evaluation of the net benefit of PSA-based screening is an “approximation” and not yet a settled science. In addition to screening policies, this also applies to our current approach to “watchful waiting,” a disease monitoring strategy also known as active surveillance. The methodology for active surveillance–including the question of who benefits and how it is administered–is still an evolving science.
Additionally, in a recent letter to the New England Journal of Medicine, Drs. Shoag, Mittal, and Hu call into question the large-scale US study that served as the basis for the 2012 USPSTF D-grade recommendation against PSA-based screening known as the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) trial. The authors of this letter conclude that the results of the PLCO trial are uninterpretable due to contamination. The authors show how a higher rate of PSA testing in the trial’s control arm (80 percent of the control group reported at least one PSA test during the trial) render a comparison with the “intervention” group less meaningful in assessing the harms and benefits of screening.
What is PCF’s message for patients and clinicians?
Every case is an individual one. It is important to talk directly with your doctor who is your best advisor and closest to your individual circumstance.
PCF supports a model of shared decision-making between patients and their health care providers. Men should discuss carefully with their doctors the harms, benefits, uncertainties and risks associated with prostate cancer screening and what kind of information a baseline PSA and digital rectal examination can offer. We encourage patients to know their risk factors such as race and family history and for primary care physicians to acknowledge that high-risk populations may warrant distinct prostate cancer detection policies and disease management.
Terms to know from this article:
Checking for disease when there are no symptoms.
The removal of cells or tissues for examination under a microscope. When only a sample of tissue is removed, the procedure is called an incisional biopsy or core biopsy. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. When a sample of tissue or fluid is removed with a needle, the procedure is called a needle biopsy or fine-needle aspiration.
Active surveillance is an option offered to patients with very low-risk prostate cancer (low grade, low stage, localized disease). Patients are monitored carefully over time for signs of disease progression. A PSA blood test and digital rectal exam (DRE) and prostate biopsy are performed at physician-specified intervals. Signs of disease progression will trigger immediate active treatment.
prostate-specific antigen (PSA): A substance produced by the prostate that may be found in an increased amount in the blood of men who have prostate cancer, benign prostatic hyperplasia, or infection or inflammation of the prostate.
The grade of a tumor depends on how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread. Grading systems are different for each type of cancer.