Posted 12/6/2019 4:10 AM (GMT -7)
Prostate-specific antigen blood tests
The prostate-specific antigen (PSA) blood test was once considered a very important diagnostic tool for men of a certain age to receive. For years, men received the test even though the benefit was unclear.
In 2009, however, based on the results of a US trial, the US Preventive Services Task Force (USPSTF) recommended against its use. In 2017, the USPSTF updated its recommendations, suggesting that providers engage in shared-decision making to discuss the benefits and drawbacks of PSA testing with their patients. The USPSTF also recommended against using the PSA test in men aged 70 years and older.
As a biomarker, PSA has several limitations. Conditions other than cancer can raise PSA levels. These conditions include benign prostatic hyperplasia and prostatitis. Furthermore, PSA levels go up with age. Conversely, drugs, chemotherapy, and obesity can lower PSA levels.
Furthermore, results from PSA blood tests aren’t always accurate, and higher levels don’t necessarily mean cancer. Thus, many men with normal PSA levels may end up receiving a diagnosis of prostate cancer. In fact, between 23% and 42% of men with prostate cancer detected by PSA test results have tumors that would not affect their health if left otherwise untreated. And while you may be tempted to think “better safe than sorry,” consider that overdiagnosis comes with risks of its own, including risk of sepsis from repeat biopsies, increased costs, and anxiety.
Here’s the conclusion of a Cochrane study on the topic:
“Any reduction in prostate cancer-specific mortality may take up to 10 years to accrue; therefore, men who have a life expectancy less than 10 to 15 years should be informed that screening for prostate cancer is unlikely to be beneficial. No studies examined the independent role of screening by DRE.”
Let’s consider a quotation taken from Dr. Atul Gawande that sheds some light on the ever-changing field of medicine, and how even our most entrenched beliefs can be dispatched:
“We look for medicine to be an orderly field of knowledge and procedure. But it is not. It is an imperfect science, an enterprise of constantly changing knowledge, uncertain information, fallible individuals, and at the same time lives on the line. There is science in what we do, yes, but also habit, intuition, and sometimes plain old guessing. The gap between what we know and what we aim for persists. And this gap complicates everything we do.”
Medicine has changed greatly, not just over the past few years, but over the centuries. But, without change, there would be no progress. We are grateful for this and look forward to whatever changes the future will bring.