A new study indicates that higher prostate cancer death rates among black men in the US may be due to a higher risk of developing preclinical prostate cancer as well as a higher risk of that cancer progressing more quickly to advanced stages. Published early online in CANCER, a peer-reviewed journal of the American Cancer Society, the study suggests that screening policies may need to be tailored to the higher-risk status of this population.
Among black men in the United States, the incidence of prostate cancer is 60 percent higher than that of white men, and their mortality rate from prostate cancer is more than twice as high. To understand why, a team from the Fred Hutchinson Cancer Research Center, the University of Michigan, and Erasmus University in the Netherlands used three models of prostate cancer incidence and prostate specific antigen (PSA) screening in the United States to estimate disease onset and progression based on prostate cancer data from 1975-2000 reported by the Surveillance, Epidemiology, and End Results program of the National Cancer Institute.
The investigators estimated that 30 percent to 43 percent of black men develop preclinical prostate cancer--prostate cancer that is not symptomatic--by age 85, a risk that is 28 percent to 56 percent higher than that among men of any race.
Among men with preclinical disease, black men have a similar risk of being diagnosed with prostate cancer (35 percent to 49 percent) compared with the general population (32 percent to 44 percent) in the absence of screening. Their risk of progression to advanced disease by the time they're diagnosed is 44 percent to 75 percent higher than in the general population, however (a 12 to 13 percent risk in black men versus a seven to nine percent risk in the general population).
"We found that the interval from getting preclinical cancer to being diagnosed is long--10 years or more on average--and is similar in black and white men. But during that interval, cancers in black men tend to progress faster," said Dr. Ruth Etzioni, a senior author on the study. "What this means is that in developing screening policies for black men, it will be important to consider beginning screening them at an earlier age and potentially screening them more frequently than would be recommended by general population guidelines." She stressed that additional research is needed to determine the best policies for prostate cancer screening in black men.
In an accompanying editorial, Lauren Wallner, PhD, MPH, of the University of Michigan, and Steven Jacobsen, MD, PhD, of Kaiser Permanente Southern California, noted that the study's findings imply that the risk/benefit trade-offs of PSA screening may be quite different for black men when compared with the general population. "As the evidence is accumulating that a 'one size fits all' screening approach to prostate cancer may not be what is most appropriate, it may be time for the conversation around PSA screening to really focus on more personalized approaches to screening in high-risk black men," they wrote.