A blood test to screen for prostate cancer may be better at doing so than experts originally thought, particularly among Black men, according to a new study.
There’s no standard test for prostate cancer, according to the US Centers for Disease Control and Prevention. Two of the more commonly used tests are a digital rectal exam and a blood test for prostate specific antigen (PSA), an enzyme that is typically higher in men with prostate cancer.
A study published Sunday in the New England Journal of Medicine Evidence looked at how successful the blood tests were for all races, and specifically for Black men, by estimating how often these tests led to over overdiagnosis and overtreatment. The researchers looked at three decades of records through 2016, the last year records were available.
Not only was the test more effective than scientists originally thought, the study determined that the net benefit is even better for Black men than for the general population.
One death was prevented for every 11 to 14 men of all races diagnosed with cancer, the study says. Among Black men, the test prevented 1 death for every 8 to 12 men diagnosed and 1 death for every 5 to 9 men treated for prostate cancer.
Previous studies found that the tests prevented 1 death for every 23 men diagnosed, and that resulted in overtreatment.
Prostate cancer is ubiquitous. With the rise in testing in the late 1980s, there was a trend to treat tumors that weren’t a real threat like the ones that were, according to the American Society of Clinical Oncology. But more recently, for tumors that don’t show a risk of progression, doctors have taken more of an active surveillance approach.
Prostate cancer is the second leading cause of cancer death in American men, behind lung cancer, according to the American Cancer Society. Out of every 100 American men, about 13 will get prostate cancer during their lifetime, according to the CDC, and 2 or 3 men will die from prostate cancer.
Black men have nearly double the risk of prostate cancer death than the general population. They also get prostate cancer more often. But Black men have been historically underrepresented in clinical trials that look at the success rate of tests and other diagnostic tools.
“These data should prompt policymakers to reconsider the utility of PSA based prostate cancer screening, particularly for Black men,” the study concluded. “The potential for overdiagnosis and overtreatment remains, although these harms may be mitigated by contemporary protocols for triaging men before biopsy and active surveillance for men with low-risk disease.”
In 2012 the United States Preventive Services Task Force issued a recommendation against PSA screening. “It was really sort of on the rocks,” said study co-author Dr. Jonathan Shoag. Shoag is an assistant professor of urology at University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine.
Shoag published a study in 2016, though, that showed that the decision was based on some studies that didn’t fully capture the benefit of screening. The USPSTF updated their recommendation to a grade C, meaning that patients should discuss such screening with their doctors. Many of the other guidelines have been unclear about whether a patient should go through PSA screening, Shoag said and it had fallen out of favor. “There are many men who are not screened a lot and we’re seeing men diagnosed with more aggressive disease because they weren’t screened,” Shoag said.
Shoag hopes this latest study will get more doctors on board with this screening.
“The story of PSA screening has been controversial, it should not be controversial. This study shows that the trade offs of screening are really beneficial,” Shoag said. “We have a test that can save men’s lives and find their cancers early.”
The study is partially funded by the Bristol Myers Squibb Foundation, which has prostate cancer drugs in development.
Dr. William Dahut, chief science officer for the American Cancer Society, said the findings are “very important. That’s not something I actually say commonly.” He was not involved in the research.
However, Dahut noted that a few practices are a little different now than when these records were collected. Doctors can also screen for prostate cancer with an MRI, for example, and a cancer diagnosis does not lead to treatment as often.
This used to be called “watchful waiting,” but Dahut said it’s actually more active than it sounds.
Depending on a person’s risk that the cancer could spread, they may be monitored closely with regular MRIs and biopsies rather than getting treatments like surgery and radiation. They will have an ongoing conversation with their doctor about how to manage the disease.
“This study should actually encourage more folks to be screened,” Dahut said. “These days, you have a lot more ability to make a more nuanced and thoughtful decision with your doctor about whether you will be treated or not for prostate cancer.
“Ultimately,” he added, “what this means is, if you find the disease and you treat it appropriately, outcomes can actually be impacted in a significant and positive way.”