Understanding PSA and its derivatives in prediction of tumor volume: Addressing health disparities in prostate cancer risk stratification.
OBJECTIVE
To address health disparities in risk stratification of U.S. Hispanic/Latino men by characterizing influences of prostate weight, body mass index, and race/ethnicity on the correlation of PSA derivatives with Gleason score 6 (Grade Group 1) tumor volume in a diverse cohort.


RESULTS
Using published PSA density and PSA mass density cutoff values, men with higher body mass indices and prostate weights were less likely to have a tumor volume <0.5 cm3. Variability across race/ethnicity was found in the univariable analysis for all PSA derivatives when predicting for tumor volume. In receiver operator characteristic analysis, area under the curve values for all PSA derivatives varied across race/ethnicity with lower optimal cutoff values for Hispanic/Latino (PSA=2.79, PSA density=0.06, PSA mass=0.37, PSA mass density=0.011) and Non-Hispanic Black (PSA=3.75, PSA density=0.07, PSA mass=0.46, PSA mass density=0.008) compared to Non-Hispanic White men (PSA=4.20, PSA density=0.11 PSA mass=0.53, PSA mass density=0.014).


METHODS
We retrospectively analyzed 589 patients with low-risk prostate cancer at radical prostatectomy. Pre-operative PSA, patient height, body weight, and prostate weight were used to calculate all PSA derivatives. Receiver operating characteristic curves were constructed for each PSA derivative per racial/ethnic group to establish optimal cutoff values predicting for tumor volume ≥0.5 cm3.


CONCLUSIONS
Increasing prostate weight and body mass index negatively influence PSA derivatives for predicting tumor volume. PSA derivatives' ability to predict tumor volume varies significantly across race/ethnicity. Hispanic/Latino and Non-Hispanic Black men have lower optimal cutoff values for all PSA derivatives, which may impact risk assessment for prostate cancer.
Departments of Radiation Oncology, University of Miami Miller School of Medicine, Miami, FL, USA.|Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA.
Felix M
FM
Chinea
Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, Miami, FL, USA.
Kirill
K
Lyapichev
Departments of Pathology, Urology, and Oncology, The Johns Hopkins Medical Institutions, Baltimore, MD, USA.
Jonathan I
JI
Epstein
Biostatistics, University of Miami Miller School of Medicine, Miami, FL, USA.|Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA.
Deukwoo
D
Kwon
Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, Miami, FL, USA.
Paul Taylor
PT
Smith
Departments of Radiation Oncology, University of Miami Miller School of Medicine, Miami, FL, USA.|Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA.
Alan
A
Pollack
Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, Miami, FL, USA.|Biochemistry, University of Miami Miller School of Medicine, Miami, FL, USA.|Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA.
Richard J
RJ
Cote
Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, Miami, FL, USA.|Urology, University of Miami Miller School of Medicine, Miami, FL, USA.|Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA.
Oleksandr N
ON
Kryvenko
D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D015992:Body Mass Index; D005500:Follow-Up Studies; D054625:Healthcare Disparities; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000208:ethnology / Q000601:surgery; D012372:ROC Curve; D012189:Retrospective Studies; D047368:Tumor Burden; D044465:White People / Q000706:statistics & numerical data*
D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen
Hispanic/Latino; health disparities; prostate cancer; prostate specific antigen; risk stratification