Tuesday, April 11, 2017
An MSK expert comments on a new US Preventive Services Task Force (USPSTF) guideline regarding a type of prostate cancer screening.
The USPSTF has issued an updated guideline for prostate-specific-antigen-based screening for prostate cancer. The new guideline states that prostate-specific antigen (PSA) testing for men between age 55 and 69 should be preceded by a conversation between doctor and patient about the risks and benefits of the test. PSA is a protein produced by the prostate gland and is commonly elevated in men with prostate cancer. For men who report prostate problems, a PSA test can help find the cause.
James Eastham, Chief of the Urology Service at Memorial Sloan Kettering, explains the pros and cons of PSA testing and what patients need to know about the new guideline.
What makes the new guideline different?
The previous guideline, which was only a few years old, recommended against PSA testing in all age groups. The USPSTF gave PSA testing a grade of D, meaning that it was likely to do more harm than good.
The new USPSTF guideline gives PSA testing a grade of C, which essentially means that there are risks and benefits and a doctor should have a discussion with a patient to help reach a decision regarding whether or not the PSA should be checked. This is the strategy that the American Urological Association advocates: It’s called shared decision-making. The new guideline says that for men between age 55 and 69, PSA testing can take place after the shared decision making conversation about pros and cons.Back to top
Why that age range: 55 to 69?
There were two large randomized studies looking at prostate cancer screening — and that was the age group included in both. It’s the group that’s been studied most.
The new guideline keeps in place the D recommendation for men over age 70 and does not provide any recommendation for men under age 55.Back to top
What’s the downside of PSA testing? Why shouldn’t it be done sometimes?
In prostate cancer, most men do not develop lethal disease. If you treated everyone who was diagnosed with prostate cancer, which is what used to be done, most men would not benefit. They would be undergoing procedures or treatments that would not improve their quantity of life but would affect their quality of life. All treatments have side effects, from sexual function to urinary function, bowel function, and more.
Even further, most men who have an elevated PSA level don’t have prostate cancer. They just have a high PSA level. These men would have psychological side effects: They’d worry about having prostate cancer when most wouldn’t. Having every man undergo a PSA test without shared decision-making can open the floodgates in terms of procedures, the diagnosis of nonlethal prostate cancer, treatments, and side effects.
Having every man undergo a PSA test every year is not what should be done. That’s what was being done before, and that’s what the USPSTF was reacting to with its D recommendation. It’s also wrong to say that we should never do PSA testing because it has been shown to save lives. We want to test the right men at the right time, following an appropriate discussion about risks and benefits.Back to top
Does the new guideline address any other specific populations?
Yes, it acknowledges that African-American men and men with a family history of prostate cancer are at a higher risk for deadly prostate cancer. But the guideline states that there is not adequate evidence to make a specific recommendation for PSA screening for either population based on that criteria alone.Back to top
What do we recommend here at MSK?
The USPSTF bases its recommendations largely on prospective trials, which the scientific community doesn’t have a lot of in the area of prostate cancer screening. We have a lot of retrospective data — where we look back on a population — but not prospective data.
Much of the retrospective data show that a PSA test done early — in a man aged 40 to 45 — will assess his risk of developing lethal prostate cancer. From that, you can put a man into one of three groups: a low-risk group (he doesn’t need PSA testing for another five years or so), an intermediate-risk group (he should get PSA testing in another year or two), and a high-risk group (he should be evaluated more closely right away). That’s how we approach the subject of screening at MSK. We want to do a PSA test early, establish risk, and then personalize future follow-up.Back to top