title: Does larger tumor volume explain the higher prostate specific antigen levels in black men with prostate cancer--Results from the SEARCH database.
abstract: OBJECTIVE
  To assess whether larger tumor volume in black men explains higher presurgical PSA levels versus white men with prostate cancer.
  
  
  METHODS
  We retrospectively analyzed 1904 men from the Shared Equal Access Regional Cancer Hospital database who underwent radical prostatectomy from 1990 to 2013. Geometric mean of tumor volume and preoperative PSA for each race were estimated from multivariable linear regression models.
  
  
  RESULTS
  There were 1104 (58%) white men and 800 (42%) black men. Black men were younger (60.2 vs. 62.9 years, p<0.001) had a higher PSA (6.7 vs. 6.0 ng/mL, p<0.001), more positive margins (47 vs. 38%, p<0.001), and seminal vesicle invasion (13 vs. 9%, p=0.007). White patients had higher clinical stage (p<0.001) and greater median tumor volume (6.0 vs. 5.3 gm, p=0.011). After multivariable adjustment (except for PSA), white men had smaller mean tumor volumes (5.2 vs. 5.8 gm, p=0.011). When further adjusted for PSA, there was no racial difference in mean tumor volume (p=0.34). After multivariable adjustment, black men had higher mean PSAs vs. white men (7.5 vs. 6.1 ng/mL, p<0.001). Results were similar after further adjusting for tumor volume: black men had 16% higher mean PSAs versus white men (7.4 vs. 6.2 ng/mL, p<0.001).
  
  
  CONCLUSIONS
  In this study of men undergoing radical prostatectomy at multiple equal access medical centers, racial differences in tumor volume did not explain higher presurgical PSA levels in black versus white men. The exact reason for higher PSA values in black men remains unclear.
authors.affiliation: Medical College of Georgia-Georgia Regents University, Augusta, GA, United States.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Klaassen
authors.affiliation: Duke University Medical Center, Durham, NC, United States.
authors.forename: Lauren
authors.initials: L
authors.lastname: Howard
authors.affiliation: Medical College of Georgia-Georgia Regents University, Augusta, GA, United States; Augusta Veterans Affairs Medical Center, Augusta, GA, United States.
authors.forename: Martha K
authors.initials: MK
authors.lastname: Terris
authors.affiliation: West Los Angeles Veterans Affairs Medical Center, West Los Angeles, CA, United States; University of California, Los Angeles School of Medicine, Los Angeles, CA, United States.
authors.forename: William J
authors.initials: WJ
authors.lastname: Aronson
authors.affiliation: San Francisco Veterans Affairs Medical Center, San Francisco, CA, United States; University of California, San Francisco, CA, United States.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Cooperberg
authors.affiliation: Oregon Health & Sciences University, Portland, OR, United States.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Amling
authors.affiliation: San Diego Veterans Affairs Medical Center, San Diego, CA, United States; University of California, San Diego, CA, United States.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Kane
authors.affiliation: Durham Veterans Affairs Medical Center, Durham, NC, United States; Cedars Sinai Medical Center, Los Angeles, CA, United States. Electronic address: stephen.freedland@cshs.org.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Freedland
mesh_terms: D000368:Aged; D044383:Black People; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D047368:Tumor Burden; D044465:White People
chemical_list: D017430:Prostate-Specific Antigen
keywords: PSA; Prostate cancer; Race; Radical prostatectomy; Tumor volume