Secondary prostate cancer screening outcomes by race in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Screening Trial.
Miller EA, Pinsky PF, Black A, Andriole GL, Pierre-Victor D
BACKGROUND: Despite disparities in prostate cancer incidence and mortality rates between black and white men, there is still insufficient data available to assess potential differences in the benefits and harms of prostate cancer screening by race. Although the Prostate, Lung, Colorectal, and Ovarian (PLCO) Screening Trial is underpowered to detect a difference by race in prostate-cancer specific mortality, because of the large study size, there are still sufficient numbers to examine secondary screening outcomes. The objective of this analysis is to examine whether differences exist between black and white participants with respect to screening false-positive rates, biopsy follow-up of men with positive screens, tumor characteristics, and overdiagnosis of prostate cancer.
METHODS: Participants from the PLCO included men aged 55-74 years at baseline. Cancer diagnoses and deaths were identified through study update questionnaires, records of biopsy procedures, and linkage with the National Death Index. Cancer characteristics were obtained by medical abstractors. We used chi-squared tests to assess differences in false-positive rates, biopsy follow-up, and tumor characteristics. We used Cox proportional hazards models to compare incidence and mortality rates adjusting for age and survival rates adjusting for Gleason scores.
RESULTS: Black men were slightly more likely (14.5%) to have a false-positive PSA test compared to white men (12.4%; P = 0.02) but less likely to have a false-positive digital rectal exam (DRE) (10.9% vs 14.2%, respectively; P < 0.001). Among all men who were screened, black men were significantly more likely to undergo a biopsy than white men (16.5% vs 13.8%, respectively [P = 0.003]) but there was no difference when limited to those with a positive PSA test. Prostate cancer tumors were more likely to be aggressive and to have metastasized in black men compared to white men. Disparities in incidence, mortality, and survival rates were comparable to those seen in population-based data.
CONCLUSIONS: There was evidence that false-positive test results differed by race and screening test. Consistent with previous studies, cancer outcomes, and tumor characteristics were all more unfavorable in black men.