Dr. George points out that the study also highlights that Asian men were significantly less likely to be diagnosed with prostate cancer within 1 year of the test.
The reasons for differences in prostate risk by race are complex, he notes. There are some clues that biologic factors may be at work. For instance, early puberty has a link to prostate cancer as it does to breast cancer, and height is also associated with a greater risk of prostate cancer, Dr. George said.
It’s not necessarily a racial association but there are some biological factors associated with prostate cancer later in life, he explained. “These may be enriched in certain populations, including northern Europeans and patients with African ancestries.”
The study also notes that Black men are more likely to die from prostate cancer than are White men, and Asian men are less likely than White or Black men to die from it.
Ms. Down said the difference in prostate cancer mortality between Black vs White men, in particular, may be related to a number of factors, and age, and lifetime risk of prostate cancer may play a major role, at least in the UK.
Should There Be Different ‘Normal’ PSA Levels for Different Races?
Dr. George says there is likely a need to change the system because a PSA level in one race may not signal the same risk it does in another. So medicine probably needs to standardize what a “normal” PSA is by race, he says, adding that he is a coauthor of an upcoming paper regarding that issue.
The lowest instances of prostate cancer were in Asian patients so this isn’t just a Black and White issue, Dr. George notes. “Being able to establish benchmarks by race and ethnicity is something that is probably needed in the field,” he says.
Dr. Kishan, on the other hand, says data from this study are not enough to support differentiating PSA levels based on race. He noted a limitation of the study is that it was not able to calculate the false-negative rate of PSA tests.
What are the Implications for Treating and Screening for Prostate Cancer
Dr. Kishan says there may be a role for increased intensity of screening, whether at an earlier age or with different intervals, but prostate cancer treatment should not differ by race.
“Our prior study, as well as others,” he says, “have shown that when you balance Black and White patients for every factor that might impact prognosis other than race — such as age, disease aggressiveness, etc. — Black men actually tend to have better outcomes than White men. Thus, it would mean potentially overtreating (i.e., causing unnecessary side effects) to increase treatment intensity purely based on race with the available data.”
According to the paper, prostate cancer incidence in men with higher PSA levels increases with increasing age, even when using age-adjusted thresholds.
Dr. George says we know from this study and other studies as well that Black men are more likely to be diagnosed with prostate at a younger age. “Therefore, we probably need to be thinking about screening Black men starting at a younger age. These are the men who are most likely to benefit from an intervention — patients who have life expectancies of 20 years or more.”