Prostate cancer is the most common cancer in men. The CDC reports that 13/100 men will have prostate cancer in their lifetime and 2-3/100 will die from it. One would assume that we would have an effective screening test for such a prevalent cancer. However, this is not the case.

The Two Tests

The prostate specific antigen (PSA) is the blood test that we currently use for prostate cancer screening. Some of you may be familiar with the finger test that was more popular 20 years ago. This is called the digital rectal exam (DRE) and was used for prostate cancer screening in the past. I’m sure you will be relieved to hear that we no longer recommend doing this unpleasant maneuver on every man at their annual physical. It is still a useful test in some situations, but I don’t want you to stress that I will be doing this routinely at your next check-up.

While a simple blood test like the PSA is a big improvement on the DRE, it is still not perfect. In fact, its far from perfect. The major issue with the PSA is the issue of sensitivity and specificity. If you have not read about this yet, read my article No Test is Perfect. The test has a good sensitivity, meaning if the level is <4.0, then its very reassuring that you do not have prostate cancer. However the specificity is not very good. This means that if the PSA is >4.0 then it could mean you have prostate cancer, or it could be from something else. Lots of other factors can cause an elevated PSA besides prostate cancer. In fact, if your PSA is elevated >4.0, it is more likely to be from something else besides prostate cancer.

False Positives

Age is the most common factor that will raise your PSA. As men age, our PSA will increase in a linear fashion. Lots of men over age 70 will have a PSA >4.0 even when they don’t have prostate cancer. This is one reason why we recommend not testing the PSA over age 69 in most men. Benign prostate enlargement is a common disorder in men that causes the prostate to increase in size. This is the condition that causes men to have more frequent urination as they get older. Its not a cancerous issue, it is usually completely benign. Still, having this prostate enlargement can cause the PSA to go up. Prostatitis is an infection of the prostate. This will cause your PSA to temporarily increase well above 50.0. Prostate stimulation from sexual activity, constipation, or even a DRE can cause a temporary elevation above 4.0.

What Are The Risks?

So what’s the big deal if the test is inaccurate? You may be surprised to learn how much trouble a false positive result can cause. Let’s say we check your PSA and it comes back elevated to an intermediate level like 7.0. At this point, we will probably recommend waiting a month and then repeating the PSA level to see if it goes down to normal, or increases or stays the same. If it stays the same or increases then we will likely recommend a prostate biopsy. This is a procedure where we use a tool to go through your rectum to collect a prostate sample through the rectal wall. The risks of this procedure include pain, bleeding, infection etc. Even the prostate biopsy can come back with mixed results. At this point, you have a discussion with your urologist about removing your prostate or watching and waiting. You can see how much unnecessary downstream testing this can cause.

What Are The Benefits?

The data that we have right now suggests that if we screen 1000 men over a 10 year period, then we will save 1 life from prostate cancer. Take a look at this excellent graphic from the USPSTF:

USPSTF Guidelines

This table below also comes from the United States Preventative Services Task Force (USPSTF)

Recommendation Summary

Population	Recommendation	Grade
Men aged 55 to 69 years	For men aged 55 to 69 years, the decision to undergo periodic prostate-specific antigen (PSA)-based screening for prostate cancer should be an individual one. Before deciding whether to be screened, men should have an opportunity to discuss the potential benefits and harms of screening with their clinician and to incorporate their values and preferences in the decision. Screening offers a small potential benefit of reducing the chance of death from prostate cancer in some men. However, many men will experience potential harms of screening, including false-positive results that require additional testing and possible prostate biopsy; overdiagnosis and overtreatment; and treatment complications, such as incontinence and erectile dysfunction. In determining whether this service is appropriate in individual cases, patients and clinicians should consider the balance of benefits and harms on the basis of family history, race/ethnicity, comorbid medical conditions, patient values about the benefits and harms of screening and treatment-specific outcomes, and other health needs. Clinicians should not screen men who do not express a preference for screening.	C
Men 70 years and older	The USPSTF recommends against PSA-based screening for prostate cancer in men 70 years and older.	D

So What Do I Tell My Patients?

Deciding whether to have a PSA test done or not comes down to my patients’ preferences. If a patient is high risk for prostate cancer due to race or family history, then I do strongly recommend getting a PSA done, because it is the only screening test we have for prostate cancer. I usually start this discussion with my patients when they turn 45. I personally have a family history of prostate cancer, so I have decided that I will have a PSA done sometime in my 40s. However, for average risk patients, the data is less clear as to whether this test will really be helpful. I try to present the recommendations in an informed way to help them make the best decision for themselves. As you can tell, this is a complex decision to make. This topic deserves a thoughtful discussion between you and your doctor to make a well informed decision. As a Wise Patient, I want you to have all the tools you need to make the right decision for you.

If you are interested in other ways to prepare for your office visit with your doctor, take a look at my other articles about Visit Preparation.

Ready to continue your wellness journey? Check out my previous article on Cholesterol.