Black men are more likely to die of prostate cancer than white men. In men with similar stages of disease, the contribution of biological vs nonbiological differences to this observed disparity is unclear.
To quantify the association of black race with long-term survival outcomes after controlling for known prognostic variables and access to care among men with prostate cancer.
This multiple-cohort study included updated individual patient-level data of men with clinical T1-4N0-1M0 prostate cancer from the following 3 cohorts: Surveillance, Epidemiology, and End Results (SEER [n = 296 273]); 5 equal-access regional medical centers within the Veterans Affairs health system (VA [n = 3972]); and 4 pooled National Cancer Institute-sponsored Radiation Therapy Oncology Group phase 3 randomized clinical trials (RCTs [n = 5854]). Data were collected in the 3 cohorts from January 1, 1992, through December 31, 2013, and analyzed from April 27, 2017, through April 13, 2019.
In the VA and RCT cohorts, all patients received surgery and radiotherapy, respectively, with curative intent. In SEER, radical treatment, hormone therapy, or conservative management were received.
Prostate cancer-specific mortality (PCSM). Secondary measures included other-cause mortality (OCM). To adjust for demographic-, cancer-, and treatment-related baseline differences, inverse probability weighting (IPW) was performed.
Among the 306 100 participants included in the analysis (mean [SD] age, 64.9 [8.9] years), black men constituted 52 840 patients (17.8%) in the SEER cohort, 1513 (38.1%) in the VA cohort, and 1129 (19.3%) in the RCT cohort. Black race was associated with an increased age-adjusted PCSM hazard (subdistribution hazard ratio [sHR], 1.30; 95% CI, 1.23-1.37; P < .001) within the SEER cohort. After IPW adjustment, black race was associated with a 0.5% (95% CI, 0.2%-0.9%) increase in PCSM at 10 years after diagnosis (sHR, 1.09; 95% CI, 1.04-1.15; P < .001), with no significant difference for high-risk men (sHR, 1.04; 95% CI, 0.97-1.12; P = .29). No significant differences in PCSM were found in the VA IPW cohort (sHR, 0.85; 95% CI, 0.56-1.30; P = .46), and black men had a significantly lower hazard in the RCT IPW cohort (sHR, 0.81; 95% CI, 0.66-0.99; P = .04). Black men had a significantly increased hazard of OCM in the SEER (sHR, 1.30; 95% CI, 1.27-1.34; P < .001) and RCT (sHR, 1.17; 95% CI, 1.06-1.29; P = .002) IPW cohorts.
In this study, after adjustment for nonbiological differences, notably access to care and standardized treatment, black race did not appear to be associated with inferior stage-for-stage PCSM. A large disparity remained in OCM for black men with nonmetastatic prostate cancer.
JAMA oncology. 2019 May 23 [Epub ahead of print]
Robert T Dess, Holly E Hartman, Brandon A Mahal, Payal D Soni, William C Jackson, Matthew R Cooperberg, Christopher L Amling, William J Aronson, Christopher J Kane, Martha K Terris, Zachary S Zumsteg, Santino Butler, Joseph R Osborne, Todd M Morgan, Rohit Mehra, Simpa S Salami, Amar U Kishan, Chenyang Wang, Edward M Schaeffer, Mack Roach, Thomas M Pisansky, William U Shipley, Stephen J Freedland, Howard M Sandler, Susan Halabi, Felix Y Feng, James J Dignam, Paul L Nguyen, Matthew J Schipper, Daniel E Spratt
Department of Radiation Oncology, University of Michigan, Ann Arbor., Department of Biostatistics, University of Michigan, Ann Arbor., Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts., Department of Radiation Oncology, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia., Department of Urology, University of California, San Francisco., Department of Urology, Oregon Health and Science University, Portland., Department of Urology, University of California, Los Angeles., Department of Urology, University of California, San Diego., Department of Urology, Augusta University, Augusta, Georgia., Department of Radiation Oncology, Cedars Sinai, West Hollywood, California., Department of Radiology, Weill Cornell, New York, New York., Department of Urology, University of Michigan, Ann Arbor., Department of Pathology, University of Michigan, Ann Arbor., Department of Radiation Oncology, University of California, Los Angeles., Department of Urology, Northwestern University, Chicago, Illinois., Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota., Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts., Department of Urology, Cedars-Sinai Medical Center, Los Angeles, California., Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina., Department of Biostatistics, University of Chicago, Chicago, Illinois.