African American Men with Prostate Cancer Treated by Simultaneous Irradiation

Abstract

Objectives: Reportedly, African American men (AAM) with prostate cancer present with more advanced disease and have worse outcomes than white men (WM). We evaluate this concept in our series of men with prostate cancer treated with modern simultaneous irradiation in a busy private practice. Materials and Methods: From 1993 to 1998, 1270 men with clinical stage T1T2N0 prostate cancer were treated by ultrasound-guided transperineal implantation of I-125 in the prostate and seminal vesicle (median dose 12,000 cGy) followed by external-beam radiation therapy (4500 cGy) including an additional 750 cGy seminal vesicle boost in men with adverse prognostic factors. None received neoadjuvant or adjuvant hormone therapy. The median pretreatment prostate specific antigen (PSA) level for 141 AAM and 1129 WM was 8.6 ng/ml and 7.1 ng/ml, respectively, a significant difference (p = 0.0001). Disease freedom is defined as achievement and maintenance of a PSA nadir of ≤ 0.2 ng/ml. The median follow-up is 24 months (range 12–66 months). Results: Disease-free survival for the entire group is 89% (± 3%) at 5 years. Overall, or when analyzed by stage, Gleason score, or age, AAM present with higher pretreatment PSA levels than WM. However, according to pretreatment PSA groups of ≤ 4.0 ng/ml, 4.1–10.0 ng/ml, 10.1–20.0 ng/ml, and > 20.0 ng/ml, the 5-year disease-free survival rates for AAM and WM in these groups are 100% and 95%, 85% and 92%, 67% and 80%, 76% and 83%, respectively. No significant difference in disease freedom is observed within the above PSA groups or by analysis of Gleason score or stage. With disease freedom as an end point, race is not a significant factor on multivariate analysis. Conclusions: AAM present with higher pretreatment PSA levels than WM both overall and when stratified by stage, Gleason score, or age. In this series, however, disease-free survival rates of AAM and WM are not significantly different overall or according to pretreatment variables. Thus, race does not appear to be an adverse prognostic factor after simultaneous irradiation.