Is prostate cancer different in black men? Answers from 3 natural history models

Abstract

Background: Black men in the United States have substantially higher prostate cancer incidence rates than the general population. The extent to which this incidence disparity is because prostate cancer is more prevalent, more aggressive, and/or more frequently diagnosed in black men is unknown.

Methods: The authors estimated 3 independently developed models of prostate cancer natural history in black men and in the general population using an updated reconstruction of prostate-specific antigen screening, based on the National Health Interview Survey in 2005 and on prostate cancer incidence data from the Surveillance, Epidemiology, and End Results program during 1975 through 2000. By using the estimated models, the natural history of prostate cancer was compared between black men and the general population.

Results: The models projected that from 30% to 43% (range across models) of black men develop preclinical prostate cancer by age 85 years, a risk that is (relatively) 28% to 56% higher than that in the general population. Among men who had preclinical disease onset, black men had a similar risk of diagnosis (range, 35%-49%) compared with the general population (32%-44%), but their risk of progression to metastatic disease by the time of diagnosis was from 44% to 75% higher than that in the general population.

Conclusions: Prostate cancer incidence patterns implicate higher incidence of preclinical disease and higher risk of metastatic progression among black men. The findings suggest screening black men earlier than white men and support further research into the benefit-harm tradeoffs of more aggressive screening policies for black men. Cancer 2017;123:2312-2319. © 2017 American Cancer Society.

Keywords: cancer epidemiology; mass screening; natural history; prostate-specific antigen; prostatic neoplasms; racial disparities; statistical methods and models.

Figure 1

Annual percentage of men receiving at least 1 PSA test based on the updated reconstruction of PSA screening patterns in the US.

Figure 2

Age-adjusted prostate cancer incidence rates per 100,000 men ages 50–84 years for black men (black line) and all races (gray line) and corresponding projections by three models (colored lines). Model projections are based on the models estimated for all races combined with PSA screening in black men and sequentially re-estimating components of natural history to allow differential risk of onset of preclinical cancer (“Onset”), risk of progression to metastasis and/or higher grade (“Progression”), and risk of clinical diagnosis (“Diagnosis”).

Figure 3

Cumulative incidence of onset of preclinical prostate cancer that would be clinically diagnosed in black men and all races projected by the models. Line segments show ages at which black men have incidence corresponding to levels estimated at age 55 in all races.