Race-based medicine and routine PSA screening in Black men
Originally posted on Common Sense Family Doctor on July 1, 2022.
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Several years ago, I asked whether routinely screening African American men for prostate cancer was warranted when evidence suggested that harms exceeded benefits in the general population. Even though many experts felt that it was, I disagreed:
What troubles me about this position is that race is as much a social construct as it is a biological one. Much of the disparity in prostate-cancer mortality between African-American and Caucasians can be explained by lower access to and quality of care, rather than a genetic predisposition for more aggressive and/or lethal cancers. In contrast to national data, studies of equal-access healthcare systems in the U.S. such as the Veterans Health Administration and the Department of Defense found no differences in prostate cancer mortality between Black and White men.
Since that time, the U.S. Preventive Services Task Force partially reversed itself and now states that "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." Individual decision-making relies in part on assessing risk factors for potentially fatal prostate cancer, but aside from family history, the only other known risk factor is Black race.
Race-based medicine's drawbacks have become increasingly evident, however, and groups across the spectrum of medicine have been working to eliminate the inappropriate use of race from clinical decision-making. In this context, a group of urologists and oncologists recently updated a 2009 analysis of the effects of PSA screening in the U.S. and concluded that the benefit to harm ratio of screening over the past 3 decades was considerably more favorable in Black men than in the American population as a whole.
So was I wrong about not approaching Black men differently in PSA screening? Or as the title of the accompanying editorial asked, "Should recommendations for cancer screening differentiate on race?" Drs. Gil Welch (who authored the original analysis of PSA screening) and Adewole Adamson observed that assuming that the effectiveness of PSA screening or the harm of overdiagnosis are not substantially modified by race, then the higher prostate cancer death rate in Black men suggests that they would be more likely to benefit from screening than men of other races.
On the other hand, they argued, "in the context of addressing health disparities, cancer screening is a massive distraction. ... Cancer-associated health disparities not biased by early detection are related primarily to unequal treatment after diagnosis, not screening." All but a small fraction of the increased risk of lethal prostate cancer in Black men is likely to be mediated by social determinants of health and structural racism rather than genetics. Shockingly, "in Black men, the median age of prostate cancer death is 76 years, 4 years older than their average life expectancy [emphasis mine]," which is a strong argument for devoting more resources to improving the lives of the >95% of Black men who die from something other than prostate cancer (e.g., heart disease, lung cancer, chronic kidney disease).
I will continue to inform Black and multiracial patients in the age group highlighted by the USPSTF about population-level risks and the (increasingly inexcusable) paucity of empiric data on the benefits and harms of PSA screening in Black men. Some will choose to be screened, some will not. But I continue to believe that race-based screening for prostate cancer - i.e., screening a man only because of the color of his skin - is the wrong approach.