African Americans experience greater prostate cancer risk and mortality than do Caucasians. An analysis of pooled phase III data suggested differences in overall survival (OS) between African American and Caucasian men receiving sipuleucel-T. We explored this in PROCEED (NCT01306890), an FDA-requested registry in over 1900 patients with metastatic castration-resistant prostate cancer (mCRPC) treated with sipuleucel-T.
OS for patients who received ≥1 sipuleucel-T infusion was compared between African American and Caucasian men using an all patient set and a baseline prostate-specific antigen (PSA)-matched set (two Caucasians to every one African American with baseline PSAs within 10% of each other). Univariable and multivariable analyses were conducted. Survival data were examined using Kaplan-Meier and Cox proportional hazard methodologies.
Median follow-up was 46.6 months. Overall survival differed between African American and Caucasian men with hazard ratios (HR) of 0.81 (95% confidence interval [CI]: 0.68-0.97, P = 0.03) in the all patient set and 0.70 (95% CI: 0.57-0.86, P < 0.001) in the PSA-matched set. Median OS was longer in African Americans than in Caucasian men for both analysis sets, e.g., 35.3 and 25.8 months, respectively, in the PSA-matched set. Similar results were observed in the all patient set. Differences were larger when treatment began at lower baseline PSA; curves were more similar among patients with higher baseline PSA. In patients with baseline PSA below the median, the HR was 0.52 (95% CI: 0.37-0.72, P < 0.001), with median OS of 54.3 versus 33.4 months. Known prognostic factors and African American race (multivariable analyses; HR: 0.60, 95% CI: 0.48-0.74, P < 0.001) were independently associated with OS. Use of post-sipuleucel-T anticancer interventions was balanced between races.
In this exploratory analysis of a registry including nearly 12% African American men with mCRPC, OS was significantly different between African Americans and Caucasians, indicating further research is warranted.
Prostate cancer and prostatic diseases. 2020 Feb 28 [Epub ahead of print]
Oliver Sartor, Andrew J Armstrong, Chiledum Ahaghotu, David G McLeod, Matthew R Cooperberg, David F Penson, Philip W Kantoff, Nicholas J Vogelzang, Arif Hussain, Christopher M Pieczonka, Neal D Shore, David I Quinn, Eric J Small, Elisabeth I Heath, Ronald F Tutrone, Paul F Schellhammer, Matthew Harmon, Nancy N Chang, Nadeem A Sheikh, Bruce Brown, Stephen J Freedland, Celestia S Higano
Tulane Medical School, New Orleans, LA, USA. ., Duke Prostate and Urologic Cancer Center, Duke Cancer Institute, Durham, NC, USA., MedStar Southern Maryland Hospital Center, Maryland, MD, USA., Center for Prostate Disease Research at the Uniformed Services University of Health Sciences, Bethesda, MD, USA., Departments of Urology and Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA., Vanderbilt University Medical Center, Nashville, TN, USA., Memorial Sloan Kettering Cancer Center, New York, NY, USA., Comprehensive Cancer Centers of Nevada, Las Vegas, NV, USA., University of Maryland School of Medicine, Baltimore, MD, USA., Associated Medical Professionals, Syracuse, NY, USA., Department of Urology, Carolina Urologic Research Center, Myrtle Beach, SC, USA., Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA., UCSF Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA., Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, USA., Chesapeake Urology Research Associates, Towson, MD, USA., Department of Urology, Eastern Virginia Medical School Urology of Virginia, Virginia, VA, USA., Dendreon Pharmaceuticals LLC, Seattle, WA, USA., Center for Integrated Research in Cancer and Lifestyle, Cedars-Sinai Medical Center, Los Angeles, CA, USA., University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA, USA.