Tuesday, July 5, 2016
Why Recommendation of the USPSTF Not to Perform PSA Based Screening, Even in High Risk Individuals is a Mistake.
By: Brian A. Stone MD, FACS with Jasper Urology Associates Brookwood Baptist Health
Prostate cancer will be diagnosed in 180,890 men in 2016 and will likely cause the deaths of another 26,120 men in the United States. It is estimated that there are over 2.8 million men living with prostate cancer in the US (2013 data). The likely unintended consequence of the United States Preventative Services Task Force has been the presentation of men in our office with higher PSA levels and more advanced prostate cancer when it is found. More alarming was the fact that this recommendation included high-risk men who have a strong family history of prostate cancer and African American men. This negative recommendation has created a dilemma for the urologist who must manage reluctant patients and prostate cancer. Even more concerning is the potential reluctance of the “gate keeper” physician to perform the PSA test in the appropriate age group or to not respect a rising PSA.
Fact: The leading cause of malpractice claims against urologists is the failure to diagnose and treat prostate cancer in a timely manner. Primary care physicians are being increasingly held liable for failing to obtain PSA testing and failure to refer patients to an urologist.
PSA or “prostate specific antigen” is a serine protease that is produced by the cells of the prostate. Both normal and cancerous cells of the prostate produce PSA. Elevated levels of PSA are “suggestive” of prostate cancer risk and are the trigger for prostate biopsies. However, PSA levels can also rise from inflammatory processes (prostatitis, instrumentation and trauma) and benign prostatic hyperplasia (BPH). PSA is also a good marker for prostatic volume. The PSA blood test is not the perfect screening tool for prostate cancer, but it is the only marker that we have for this disease.
Fact: PSA is found primarily in the epithelial cells of the prostate and semen. Low concentrations of PSA have been found in urethral glands, endometrium, normal breast tissue, breast milk, salivary glands and urine (males & females).
The goal of prostate cancer early detection has always been to detect potentially aggressive and lethal forms prostate cancer at its earliest stages when treatment can mitigate the morbidity and mortality from the disease. However, it has become evident that “blanket” screening does detect non-lethal cancers and the treatments are not without potential side effects. Prostate biopsy also carries a very low, but real, risk of sepsis requiring in-patient treatment. It is clear that common sense use of PSA and shared decision making with the patient can be useful in protecting those patients who are at high risk of being diagnosed with prostate cancer.
Fact: Since PSA was introduced, 75% of men diagnosed with prostate cancer have non-palpable disease.
The USPSTF recommendation is based on one study, the PLCO trial (Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial), whose methodology was severely flawed. Over 90% of the men in the control group (allegedly not screened) had indeed been screened contaminating the data. Additionally, African American men only represented 4% of the cohort in this pivotal study. This was a critical flaw in a study that has been used to make a negative determination about a test that has saved so many lives. I base this statement on the fact that mortality had steadily declined since the introduction of PSA testing in 1992 based on SEER mortality statistics.
Fact: Prior to the introduction of PSA 70% of men with prostate cancer presented with extraprostatic or metastatic disease. Since the introduction of PSA, fewer that 3% of men have metastasis at diagnosis.
In March of this year, the Centers for Medicare and Medicaid Services temporarily suspended development of a proposed “non-recommended PSA based screening” measure that would have discouraged PSA screening in all men. USPSTF is currently in the process of updating its recommendations for prostate cancer screening. The decision makers (both in policy and the insurance side) must make very well educated and thoughtful considerations about the fate of the PSA blood test, particularly with the available data that is highly supportive of intermittent PSA testing. This reduces the costs and harms of screening while preserving the benefits of yearly testing (based on the AUA guideline for early detection of prostate cancer).
Fact: Men who begin PSA testing and digital rectal examinations at the recommended age (depending on risk factors) and are eventually diagnosed with prostate cancer and treated, have a 5-year survival of 100% and 10-year survival of over 90%.
Physicians have sworn the Hippocratic oath, which states that above all things “do no harm”. It is obvious to me that the blanket denial of educated, patient involved prostate cancer screening in high risk populations would be a violation of our oath.