Who Should Get a Prostate Cancer Screening and When?
Sep 05, 2017 Cedars-Sinai Staff
Once men reach their 50s, many wonder if the safe play is to get screened for prostate cancer, which is the second most common form of cancer in men (skin cancer is #1). Men who have a family history of prostate cancer or other risk factors may even pull the trigger on a prostate-specific antigen (PSA) test while still in their 40s.
The question of when men should start getting prostate cancer screening is somewhat controversial.
Prostate cancer screening can be controversial, and guidelines have gone back and forth, with a recent update coming from the US Preventive Services Task Force in April 2017.
Understanding the controversy
PSA is a protein that's made by the prostate gland and is passed on through the semen as part of normal function in fertility. A PSA test is simple blood test that reveals the level of prostate-specific antigen in a patient's blood.
Even with a healthy prostate, PSA leaks into the bloodstream at very low levels. Anything that causes more leakage raises those levels. Prostate cancer can cause elevated PSA levels, but so can a number of other things, including a naturally large prostate, inflammation, and recent trauma impacting the prostate.
Dr. Stephen Freedland, a urologist and director of the Cedars-Sinai Center for Integrated Research in Cancer and Lifestyle (CIRCL), explains that there is no doubt that PSA tests can lead to the early discovery of cancers. But testing can also result in false positives, which can lead to unnecessary treatment and testing, including biopsies that carry a risk of infection.
"Can we treat people selectively to reduce the risk of death from aggressive cancers while trying to minimize the harm of picking up indolent cancers or what we call false positives? That's the controversial question."
There is no doubt that PSA tests can lead to the early discovery of cancers. But testing can also result in false positives.
For a period of time, the US Preventive Services Task Force believed that the harms of PSA tests outweighed the benefits. "But they've changed that position," says Dr. Freedland. "They now believe there is a balance of harm and benefit that doctors should explain to patients to enable an informed decision."
The chief concern is that a biopsy of the prostate carries a 2-4% risk of significant infection. If that sounds like a low number, keep in mind that approximately one million men in the US get a biopsy because of an abnormal PSA test each year. That means 20,000-40,000 men will develop a severe infection within the prostate that spreads to the bloodstream and requires hospital admission to treat.
Another option: digital rectal exams
Most prostate biopsies are driven by PSA results. Urologists also use the digital rectal exam, or DRE.
"The American Urological Association (AUA) hasn't recommended rectal exams because there has yet to be a randomized trial in which some men get the rectal exam and some don't. Based on who lives and dies, this would show if rectal exams have value," says Dr. Freedland. "Many people, myself included, think they do have value. It's part of the evaluation that we use even if it's not officially in our guidelines."
The DRE may cause momentary discomfort, but it can also detect prostate cancer for those patients with normal PSA levels. "We use the exam because we think it should work and be helpful, even if it hasn't been studied," Dr. Freedland adds. "Most people are screened with PSA and DRE."
Age and the PSA test
Again, the question of when men should start getting prostate cancer screening is somewhat controversial. Guidelines from the US Preventive Services Task Force and the AUA suggest that men 55-69 should work with their doctor to make an individualized decision. Dr. Freedland points out that historically, men at age 50 have begun receiving these screenings, and those who are African-American or have a family history of prostate cancer often start testing at 45.
"There is data that a PSA in your 40s can be very prognostic. It can really tell what the future holds. I was on the guideline committee that made these recommendations. We are well aware of that data. But here's the thing: We weren't aware of data that showed knowing this information could change the outcome for men in their 40s."
Despite the guidelines, Dr. Freedland recommends that patients in their 40s have the PSA test.
The challenge is that there are no definitively helpful lifestyle changes. The goal is to lower the prostate cancer risk—not just the PSA level. But at the moment, there is no proof that eating a particular diet or losing weight will have that benefit.
Still, many physicians believe that adjustments to diet and weight can reduce the risk of prostate cancer, which is something actively being pursued within CIRCL. That's why, despite the guidelines, Dr. Freedland and others recommend that patients in their 40s have the PSA test.
"It needs to be an informed discussion," he cautions. "But eventually, the majority of American men do get PSA tested. We try to be rational about who we move to biopsy based upon the absolute PSA level and changes over time, family history, race, or other medical problems. We put all of this information together. Personally, at age 45, I had my PSA test done a year ago. It's 'practice what you believe.'"