Black men should be screened earlier for prostate cancer

By Will Boggs MD

NEW YORK (Reuters Health) - Compared with white men, black men develop preclinical prostate cancer at an earlier age and face a higher risk of metastatic progression, researchers report.

"Black men are not an average-risk population when it comes to prostate cancer and they should be recognized as such,” Dr. Ruth Etzioni from Fred Hutchinson Cancer Research Center, Seattle, Washington told Reuters Health by email. “Guidelines made for the general population do not apply to them. It is important for black men to be well informed about the potential benefits and risks of prostate cancer screening so that they can make a decision that is right for them. It is appropriate for this to happen at an earlier age than is recommended for the general population.”

The incidence of prostate cancer is 60% higher among black men than among white men, and black men are more than twice as likely to die from it. Several studies have explored the likely drivers of these racial disparities without reaching definitive conclusions.

Dr. Etzioni and colleagues used prostate cancer incidence trends in the Surveillance, Epidemiology, and End Results (SEER) program to investigate and explain the differences in the natural history of prostate cancer in black and white men.

Relative to the general population, black men were less likely to receive at least one prostate-specific antigen (PSA) test in all but the youngest ages, with the greatest disparities in PSA testing in the oldest age groups.

Based on the results of three natural history models, the risk of developing preclinical disease is 24% to 29% in the general population. Among black men, the risks rise to 30% to 43% (28% to 56% higher than those of the general population).

Similarly, the risks of clinical diagnosis are 33% to 70% higher in black men than in the general population, according to the April 24th report online in Cancer.

Among men who already have preclinical disease, however, the risk of clinical diagnosis is similar for blacks and all races, and this translates into times from disease onset to diagnosis that are very similar for black men and for the general population.

Black men, however, are 44% to 75% more likely than the general population to develop metastasis before diagnosis.

"The model results consistently demonstrated that the risk of onset of a preclinical prostate cancer explains a large majority of the observed incidence disparities," the researchers note. "On the basis of these results, we conclude that black men have more preclinical and progressive prostate cancer than men in the general population. They are more likely to develop prostate cancer at a younger age, and they are more likely to progress to a metastatic state and/or higher grade before clinical diagnosis."

“Although black men may have a higher risk of disease that will spread without screening, they are subject to similar risks of overdiagnosis and potential overtreatment as the general population,” Dr. Etzioni said. “They should recognize that if they decide to screen and they are diagnosed with a low-risk (low grade, low volume) cancer, active surveillance or another conservative treatment approach will be a preferred option.”

“There are no screening trials that address black men specifically or in the numbers needed to make proper inferences,” she said. “Therefore, we need to use statistical modeling to fill in the gaps. We used three different models, and the qualitative conclusions are robust and send a clear message that risk stratification by race is appropriate when making policies for prostate cancer screening.”

“We have not figured the exact most preferred approach for black men,” Dr. Etzioni added, “but if the U.S. Preventive Services Task Force (USPSTF) is recommending that average-risk men start shared decision making about prostate cancer at age 55, then probably black men should be doing this at age 50 or between 45 and 50 if we agree that we want to provide black men the same opportunity to improve their chances (in terms of reducing the burden of disease) as we are providing to the average risk population.”

Dr. Lauren P. Wallner from the University of Michigan in Ann Arbor, who co-authored an editorial related to this report, told Reuters Health by email, "While the results of the study were not surprising, they are interesting and very timely because they inform the discussion about the appropriateness of having a ‘one size fits all’ approach to prostate cancer screening. The findings that African American men are much more likely to progress to metastatic disease prior to diagnosis when compared to the general population suggest that early detection via screening may be particularly important in this group.”

“However,” she said, “studies directly evaluating the effectiveness of PSA screening in African American men are still lacking. Therefore, it remains unknown whether PSA screening offers African American men a greater benefit in terms of preventing mortality due to prostate cancer when compared to the general population.”

“Because of the lack of data to inform whether the benefits of PSA screening outweigh the risks in African American men specifically, the recently revised USPSTF PSA screening recommendations still do not recommend a different approach to screening African American men for prostate cancer,” Dr. Wallner said. “However, this study provides additional evidence to support their recommendation that clinicians discuss the increased risk of developing and dying of prostate cancer with their African American patients to help them make informed and personalized screening decisions.”

Dr. Firas Abdollah from Henry Ford Hospital and Vattikuti Urology Institute, Detroit, Michigan told Reuters Health by email, “Unfortunately, the currently available trials addressing the role of PSA screening have included a very limited number of black men, and as such are not necessarily generalizable to this population. The issue of under-representing minorities is common to many clinical trials, and this should be avoided in future trials.”

“Primary care physicians should be aware that prostate cancer is generally more aggressive in black men, and might rapidly proceed from preclinical disease to metastatic disease,” he said. “As such, PSA screening should be considered more strongly in these individuals, despite the limitation of this test.”

SOURCE: http://bit.ly/2q41CxL and http://bit.ly/2oJnvP2

Cancer 2017.

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