On May 8, 2018, the U.S. Preventive Services Task Force, an independent medical panel composed of volunteer doctors, published updated PSA screening recommendations. The latest guidelines include
- For men ages 55-69 the decision to have periodic PSA testing to screen for prostate cancer (PCa) should be up to the individual after consulting with his doctor on the merits and risks for him
- For men age 70 and older, PSA screening is not recommended
- For populations at higher risk (e.g. men with a first-degree relative who had PCa; African American men) the USPSTF called for more research to help establish guidelines)
The swinging pendulum
It has been about 25 years since the PSA era began. Since then, screening trends have gone from one extreme to another. In the mid-to-late 1990s, PSA screening was everyone’s darling because a few studies reported that early detection saved lives. Therefore, all men were encouraged to have an annual blood draw starting as early as age 40, but certainly no later than age 50.
In less than 10 years, a backlash occurred as the harms of PSA screening – overdetection and overtreatment of insignificant PCa—became evident. Men with low grade PCa that was highly unlikely to kill them were undergoing whole gland treatments (surgery, radiation) that left them dripping urine and unable to have spontaneous erections. But they put up with it, believing that they would never have to worry about PCa again. In the face of such tragedy, Richard Ablin, the man who put the PSA test on the map, protested its misuse: “The test’s popularity has led to a hugely expensive public health disaster.”[i]
In 2008, the USPSTF had recommended against PSA screening for men older than age 75. Four years later, after reviewing considerable evidence, they wrote, “There is no apparent reduction in all-cause mortality…Many more men in a screened population will experience the harms of screening and treatment of screen-detected disease than will experience the benefit.” As a result, their 2012 conclusion came across as a broad mandate: “The U.S. Preventive Services Task Force (USPSTF) recommends against prostate-specific antigen (PSA)-based screening for prostate cancer.” [ii]
Throwing the baby out with the bath
What happened next exemplifies the law of unintended consequences. Many men simply stopped having the test, and many doctors simply told their patients it did more harm than good. In short, for the next 4-5 years, countless men skipped the blood draw. This turned out to be tossing the baby out with the bath, as a different pendulum – statistics – would soon show.
At the start of the PSA era in the mid-1990s, the PCa statistical pendulum began a steady swing toward reduced deaths from PCa (50% decline) and fewer men with PCa spread at the time of diagnosis (70% decline). This trend took many years to become evident, so it’s possible that the data wasn’t clear in 2008 and 2012 when the USPSTF weighed in with their guidelines.
However, a statistical analysis published in 2017 revealed that for some years after the 2012 recommendation, the PCa pendulum was starting to reverse its arc. In a study of over 1 million men from the SEER database (2004-2013). The study authors found the following at the time of diagnosis:
In older patients, 6.6% of men presented with distant metastases in 2004 compared with 12% in 2013, and this did remain significant in the adjusted analysis. The rate of intermediate- or high-grade disease also rose from 58.1% to 72% (P < .01) in these men.[iii]
Thus, it appears that as PSA screening began dropping off first among older men in 2008, then all men in 2012, men were being diagnosed with worse disease than if they had been screened.
The dilemma, and how to resolve it
To screen or not to screen? That is the dilemma, because lives have indeed been saved despite the fact that the PSA test really can’t show if a man has PCa or not. All it can show is that something going on in the prostate gland (infection, inflammation, BPH, physical stimulation like riding a bike or having sex) is releasing more PSA (a cell-surface protein) into the bloodstream. However, each year a million biopsies are performed in this country on men whose PSA is elevated. In turn, tens of thousands will undergo treatment that may leave them with impotence or incontinence. Or, men will avoid screening only to be diagnosed when the cancer is far progressed (late stage disease). This is why the USPSTF advises doctors to talk with their patients about the risks/rewards ratio.
Thankfully, new blood and urine tests for PCa-specific biomarkers are rapidly becoming available. This means that using better analysis on the same blood draw can spare countless men from having an unnecessary biopsy.
In addition, the Sperling Prostate Center resolves the PSA dilemma through imaging. One 3T multiparametric MRI (3T mpMRI) scan is worth 1,000 words written in a detailed biopsy report. If an area suspicious for significant PCa is seen, an MRI-guided targeted biopsy provides an accurate diagnosis using only a minimal number of needles. And if no suspicious areas are seen, there’s no need for a biopsy. Studies show that PSA + 3T mpMRI eliminates overdetection and overtreatment. Why skip the PSA blood test and risk late-stage PCa diagnosis? Our Center is here to resolve the PSA dilemma.
[i] Richard J. Ablin. “The Great Prostate Mistake.” NY Times, March 9, 2010. https://www.nytimes.com/2010/03/10/opinion/10Ablin.html
[iii] Dave Levitan. “Increasing Rate of Prostate Cancer Metastasis at Diagnosis in Older Men.” Cancer Network, Jan. 5, 2017. http://www.cancernetwork.com/genitourinary-cancers/increasing-rate-prostate-cancer-metastases-diagnosis-older-men