2008 Annual Meeting Abstracts

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Racial Differences of Estimated Tumor Volume and the Effect on PSA-free survival among European Americans and African-Americans.
Benjamin M Brucker, Meredith Bergey*, Matthew Resnick, Seema Sonnad*, Alan J. Wein, Keith VanArsdalen, S. Bruce Malkowicz
University of Pennsylvania, Philadelphia, PA

Introduction: Larger estimated tumor volume (TV) in radical prostatectomy (RP) specimens has been suggested as a risk factor predicting shorter PSA-Free survival (PSAFS). Recent work has suggested African-American (AA) men exhibit larger TV than European American (EA) men. We examined a prospectively maintained RP database from 1991 to 2005 to determine if differences in TV between races would account for racial disparities in PSAFS.
Methods: There were 2,163 patient evaluated. 1,877 patients were classified as EA and 286 patients as AA. A TV cutoff of >10% was used. Chi-square, univariate and multivariate regression analysis were utilized.
Results: 39% of EA and 49% of AA had TV>10% (p=0.004). The percentage of patients with TV >10% increase with increasing BMI. The percentages were 35%, 41% and 45% in underweight/normal, overweight and obese patients respectively (p=0.005). Mean follow-up was 49.38 months. TV remained a risk factor when controlling for age, psa, Gleason score, prostate volume, race, and BMI (HR=2.18 95%CI 1.63-2.90, p<0.001). TV was a significant risk factor in the subset of EA, but not in AA (HR=2.13, 95%CI 1.55-2.92 p<0.001 and HR=2.16, 95%CI 0.99-4.72 p=0.054 respectively).
Conclusions: Larger TVs were seen in AA men. TV >10% had a negative impact on PSAFS when controlling for race and BMI. When EA men were analyses independently this effect remained, but only neared significance in AA men. The impact of tumor volume should be considered in future studies comparing AA to EA patients.

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