Effect of race on biochemical disease-free outcome in patients with prostate cancer treated with definitive radiation therapy in an equal-access health care system: radiation oncology report of the Department of Defense Center for Prostate Disease Research.
OBJECTIVE
To report on the first collaboration of the Department of Defense Center for Prostate Disease Research concerned with the relationship between African American race and biochemical disease-free outcomes after definitive radiation therapy.


METHODS
Information from the medical records of 1,806 patients (1,349 white, 343 African American, 42 of "other" races, and 72 of "unknown" races) treated with definitive radiation therapy between 1973 and 2000 was reviewed. Patients receiving adjuvant hormonal therapy or postoperative adjuvant or salvage radiation therapy were excluded. Biochemical failure was calculated in over 96% of cases by using ASTRO criteria; patients with fewer than three follow-up visits were considered to have biochemical failure with a prostate-specific antigen (PSA) value more than 10-fold the previous value or with any value greater than 50.0 ng/mL. Median radiation therapy doses were similar. The median follow-up was 58.4 months. Kaplan-Meier tests, Cox proportional hazards regression analysis, and log-rank tests were used for data analysis.


RESULTS
There was no statistically significant difference in biochemical disease-free survival according to race when patients were stratified according to T stage. African American race conferred a negative prognosis for patients with lesions of Gleason biopsy score 7 (P =.004) but not for patients with lesions of Gleason score 2-4 (P =.14), 5-6 (P =.79), or 8-10 (P =.86). Similarly, African American race conferred a negative prognosis in patients with PSA values of 20.1-50.0 ng/mL (P =.01) at presentation but not in patients with PSA values less than or equal to 4.0 ng/mL (P =.84), 4.1-10.0 ng/mL (P =.71), 10.1-20.0 ng/mL (P =.75), or above 50.0 ng/mL (P =.15) at presentation. At multivariate analysis, race was not a statistically significant predictor of outcome.


CONCLUSIONS
In the equal-access health care system of the Department of Defense, African American race is not associated with a consistently negative prognosis in patients treated with definitive radiation therapy for prostate cancer. Race appears to confer a negative prognosis only in patients with advanced disease at presentation.
Johnstone
Peter A S
PA
Naval Medical Ctr, San Diego, Calif 92134-1014, USA. pajohnstone@nmcsd.med.navy.mil
Kane
Christopher J
CJ
Sun
Leon
L
Wu
Hongyu
H
Moul
Judd W
JW
McLeod
David G
DG
Martin
Douglas D
DD
Kusuda
Leo
L
Lance
Raymond
R
Douglas
Robert
R
Donahue
Timothy
T
Beat
Michael G
MG
Foley
John
J
Baldwin
Dalton
D
Soderdahl
Douglas
D
Do
Jason
J
Amling
Christopher L
CL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D044383:Black People; D016208:Databases, Factual; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006297:Health Services Accessibility; D006801:Humans; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D009367:Neoplasm Staging; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000208:ethnology / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D012189:Retrospective Studies; D015996:Survival Rate; D044465:White People; D001741:Black or African American
D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen