I m p a c t o f R a c e o n P r o s t a t e - S p e c i fi c A n t i g e n O u t c o m e A f t e r Radical Prostatectomy for Clinically Localized Adenocarcinoma of the Prostate By Chaundre K. Cross, Delray Shultz, S. Bruce Malkowicz, William C. Huang, Richard Whittington, John E. Tomaszewski, Andrew A. Renshaw, Jerome P. Richie, and Anthony V. D’Amico Purpose: To compare prostate-specific antigen (PSA) outcome after radical prostatectomy (RP) for prostate cancer in African-American and white men using previously established risk groups. Patients and Methods: Between 1989 and 2000, 2,036 men (n ⴝ 162 African-American men, n ⴝ 1,874 white men) underwent RP for clinically localized prostate cancer. Using pretreatment PSA, Gleason score, clinical T stage, and percentage of positive biopsy specimens, patients were stratified into low- and high-risk groups. For each risk group, PSA outcome was estimated using the actuarial method of Kaplan and Meier. Comparisons of PSA outcome between African-American and white men were made using the log-rank test. Results: The median age and PSA level for AfricanAmerican and white men were 60 and 62 years old and 8.8 and 7.0 ng/mL, respectively. African-Americans had a statistically significant increase in PSA (P ⴝ .002), Gleason score (P ⴝ .003), clinical T stage (P ⴝ .004), and percentage of positive biopsy specimens (P ⴝ .04) at presentation. However, there was no statistical difference in the distribution of PSA, clinical T stage, or Gleason score between racial groups in the low- and high-risk groups. The 5-year estimate of PSA outcome was 87% in the low-risk group for all patients (P ⴝ .70) and 28% versus 32% in African-American and white patients in the high-risk group (P ⴝ .28), respectively. Longer follow-up is required to confirm if these results are maintained at 10 years. Conclusion: Even though African-American men presented at a younger age and with more advanced disease compared with white men with prostate cancer, PSA outcome after RP when controlled for known clinical predictive factors was not statistically different. This study supports earlier screening in African-American men. J Clin Oncol 20:2863-2868. © 2002 by American Society of Clinical Oncology. PPROXIMATELY 198,100 new cases of prostate cancer are expected in the United States during 2001. Secondary to the introduction of prostate-specific antigen (PSA) screening, incidence rates increased dramatically between 1988 and 1992. From 1992 to 1998, AfricanAmerican men were almost two times as likely to be diagnosed with prostate cancer compared with white men (234.2/100,000 men v 144.6/100,000 men, respectively). Incidence rates for African-American men have declined between 1992 and 1998 by 4.0% per year. However, white men have experienced more of a decline in incidence rates during this 7-year period (5.7% per year).1,2 Also, African-American men were twice as likely to die of prostate cancer in comparison with white men between 1992 and 1998 (53.1/100,000 men and 22.4/100,000 men, respectively). From 1994 to 1998, prostate cancer death rates declined for white and African-American men (4.7% and 3.0%, respectively).1,2 The reason for the discrepancy of worse incidence and death rates among African-American men in comparison with white men in the United States is still debated. More biologic, aggressive cancer has been proposed as one possible explanation given for the higher PSA level and younger age at presentation,3-14 as well as more multifocal disease on autopsy,15,16 higher prevalence of (allegedly) high-risk alleles, such as CAG repeat,17-20 vitamin D bind- ing protein,21 and SRD5A2 gene,22 a higher testosterone level in younger men,23,24 and adverse pathologic factors after radical prostatectomy (RP)25-29 in African-American men compared with white men. Socioeconomic factors such as income, education, nutrition, and screening have also been cited as factors contributing to the more aggressive and advanced stage of prostate cancer in African-American men.30-33 Studies to date have suggested that when patients with early-stage prostate cancer are stratified by pretreatment tumor characteristics, PSA outcome is not different between ethnic groups.34,35 Limitations of these studies include A From the Departments of Radiation Oncology, Pathology, and Urology, Brigham and Women’s Hospital and Dana-Farber Cancer Institute, Boston, MA; and Department of Mathematics, Millersville University, Millersville, and Departments of Urology, Radiation Oncology, and Pathology, Hospital of University of Pennsylvania, Philadelphia, PA. Submitted November 14, 2001; accepted March 18, 2002. Address reprint requests to Chaundre Cross, MD, and Anthony D’Amico, MD, Department of Radiation Oncology, Brigham and Women’s Hospital, 75 Francis St, L-2 Level, Boston, MA 02215; email: [email protected] © 2002 by American Society of Clinical Oncology. 0732-183X/02/2012-2863/$20.00 Journal of Clinical Oncology, Vol 20, No 12 (June 15), 2002: pp 2863-2868 DOI: 10.1200/JCO.2002.11.054 Downloaded from jco.ascopubs.org on June 15, 2014. For personal use only. No other uses without permission. Copyright © 2002 American Society of Clinical Oncology. All rights reserved. 2863 2864 CROSS ET AL Table 1. Pretreatment Characteristics of All Patients White (n ⫽ 1,874) Parameter Median age, years Median PSA, ng/mL PSA ⬍ 4 ng/mL 4-10 ng/mL 10-20 ng/mL ⬎ 20 ng/mL No. African-American (n ⫽ 162) % No. 62 7.0 224 1151 356 143 % P 60 8.8 12.1 61.4 19.0 7.5 13 83 46 20 8.0 51.2 28.4 12.4 .002 Gleason grade 2-6 7 8-10 1384 376 114 73.8 20.1 6.1 108 33 21 66.6 20.4 13.0 .003 Stage* T1c T2a T2b T2c 866 632 208 168 46.2 33.7 11.1 9.0 57 66 14 25 35.2 40.8 8.6 15.4 .004 Percentage of positive biopsy specimens ⱕ 50% ⬎ 50% 1462 412 78.0 22.0 115 47 71.0 29.0 .040 *1992 AJCC clinical staging system. adjuvant therapy given after local therapy and a lack of consistent definition of the risk groups. In this analysis, patients with clinically localized prostate cancer from the Hospital of University of Pennsylvania (HUP), Philadelphia, PA, and Brigham and Women’s Hospital (BWH), Boston, MA, treated with RP and no adjuvant therapy formed the study cohort. PSA outcome for African-American and white men were compared using a previously established risk group stratification based on the PSA, Gleason score, clinical T stage, and percentage of positive biopsy specimens.36,37 PATIENTS AND METHODS Patient Population Between 1989 and 2000, 2,036 men were treated with RP for PSA detected or clinically palpable localized prostate cancer at the BWH and the HUP. Patients who received neoadjuvant androgen-suppression therapy, adjuvant radiation, or both were excluded. One hundred sixty-two African-American men and 1,874 white men were included in this study. Table 1 lists the preoperative clinical characteristics of the entire study cohort. Preoperative Staging In all cases, staging evaluation included a history and physical examination, including a digital rectal examination (DRE), serum PSA, computed tomography scan of the pelvis or an endorectal and pelvic coil magnetic resonance imaging scan of the prostate and pelvis, bone scan, and a transrectal ultrasound-guided needle biopsy of the prostate with Gleason score histologic grading.38 Whereas during the study period, bone scans, magnetic resonance imaging, or computed tomography scans were obtained routinely, on this day they would only be obtained in patients with high-risk disease. A sextant biopsy was performed using an 18-gauge Tru-Cut needle (Travenol Laboratories, Deerfield, IL). Sextant biopsy specimens were obtained in the majority of RP-managed patients at HUP (56%) and BWH (75%). The remaining 44% of patients at HUP had fewer than six (18% of patients) or more than six (26% of patients) biopsy specimens. The clinical stage was obtained from the DRE findings using the 1992 American Joint Committee on Cancer (AJCC) staging system.39 Radiologic and biopsy information was not used to determine clinical stage. The PSA level was obtained on an ambulatory basis before radiologic studies and the biopsy procedure. All pretreatment PSA values were obtained within 1 month of the date of the surgery. PSA measurements40 were made using the Hybritech (Beckman Coulter Inc, Fullerton, CA), Tosoh (Tosoh Inc, San Francisco, CA), or Abbott (Abbott Laboratories, Abbott Park, IL) assays. Treatment and Histopathologic Assessment A referee genitourinary pathologist reviewed the diagnostic biopsy specimens for all patients undergoing surgery at the HUP (J.E.T.) or BWH (A.A.R.). Surgical treatment consisted of a retropubic RP and bilateral pelvic lymph node sampling. If the intraoperative frozen sections of any sampled lymph node were positive for carcinoma, then RP was aborted. Evidence of extracapsular extension, positive margin, and seminal vesicle invasion were noted and recorded. Downloaded from jco.ascopubs.org on June 15, 2014. For personal use only. No other uses without permission. Copyright © 2002 American Society of Clinical Oncology. All rights reserved. 2865 IMPACT OF RACE ON PSA OUTCOME Table 2. Pretreatment Characteristics of Low- and High-Risk Patients Low-Risk Patients White (63%) (n ⫽ 1,177) Parameters No. PSA ⬍ 4 ng/mL 4-10 ng/ mL 10-20 ng/ mL ⬎ 20 ng/ mL High-Risk Patients African-American (45%) (n ⫽ 73) % No. % 182 897 15.5 76.2 10 59 98 8.3 4 White (37%) (n ⫽ 697) P African-American (55%) (n ⫽ 89) No. % No. % 13.7 80.8 42 254 5.7 36.4 3 24 3.4 27.0 5.5 258 37.4 42 47.2 143 20.5 20 22.4 .59 Gleason score 2-6 7 8-10 1032 145 87.6 12.4 68 5 93.2 6.8 .15 352 231 114 50.5 33.1 16.4 40 28 21 45 31.5 23.5 .16 Stage* T1c T2a T2b T2c 672 439 66 57.1 37.3 5.6 36 36 1 49.3 49.3 1.4 P .23 194 193 142 168 27.8 27.7 20.4 24.1 21 30 13 25 24 33.7 14.6 27.7 .06 .34 *1992 AJCC clinical staging system. Follow-Up The median follow-up duration for the entire cohort was 42 months (range, 6 to 132 months). The patients were examined 1 month after surgery and then at 3-month intervals for 2 years, every 6 months for 5 years, and annually thereafter. At each follow-up appointment, the serum PSA level was measured before the DRE was performed. No patients were lost to follow-up. Statistical Analysis PSA failure was defined as two detectable (⬎ 0.2 ng/mL) PSA values obtained after an undetectable measurement. The time of PSA failure was taken as the time of the first detectable PSA. Time zero was the date of RP. If a PSA never became undetectable after surgery, then PSA failure was considered to have occurred at time equal to zero. PSA outcome was defined as PSA failure-free survival at 5 years, which was estimated using the actuarial method of Kaplan and Meier41 and graphically displayed. Three risk groups were defined36,37 based on the pretreatment PSA level, biopsy Gleason score, and 1992 AJCC T stage. Low-risk patients had a preoperative PSA level of ⱕ 10 ng/mL, a biopsy Gleason score of ⱕ 6, and 1992 AJCC clinical stage T1c or T2a disease. High-risk patients had a PSA level of greater than 20 ng/mL, a biopsy Gleason score of ⱖ 8, or 1992 AJCC clinical stage T2c disease. The remaining patients with ⱕ 50% or more than 50% positive biopsy specimens were classified as low- and high-risk, respectively, based on a previous study showing the importance of the percentage of positive biopsy specimens in intermediate-risk patients. PSA outcome was reported for the lowand high-risk groups. Specifically, using a log-rank test,42 PSA outcome was compared in low- and high-risk groups stratified by race. RESULTS Pretreatment Clinical Characteristics The median age for white and African-American men was 62 and 60 years, respectively, and the median PSA level was 7.0 and 8.8 ng/mL, respectively (Table 1). The pretreatment clinical factors for all patients revealed more advanced disease in the African-American cohort (Table 1). African-American men had a statistically significant increase in PSA (P ⫽ .002), Gleason score (P ⫽ .003), clinical T stage (P ⫽ .004), and percentage of positive biopsy specimens (P ⫽ .04). Also, 55% of the AfricanAmerican patients were in the high-risk group versus 37% of the white patients. However, there was no statistical difference in the distribution of PSA, clinical T stage, or Gleason score between racial groups within each of the lowand high-risk groups as summarized in Table 2. PSA Failure-Free Survival The median follow-up for African-American and white patients in the low- and high-risk groups was not statistically different. Specifically, the median follow-up for African-American and white men in the low-risk groups for patients censored at the time of PSA failure was 38 and 35 months, respectively. For high-risk groups, it was 22 and 23 Downloaded from jco.ascopubs.org on June 15, 2014. For personal use only. No other uses without permission. Copyright © 2002 American Society of Clinical Oncology. All rights reserved. 2866 CROSS ET AL Fig 1. PSA failure-free (bNED) survival by race for low-risk patients (P ⴝ .70). bNED, biochemical no evidence of disease. months, respectively. The 5-year estimate of PSA outcome was 87% in the low-risk group for both African-American and white patients (P ⫽ .70) and 28% versus 32% in African-American and white patients, respectively, in the high-risk group (P ⫽ .28). These results are illustrated in Figs 1 and 2. DISCUSSION Previous studies have attempted to compare PSA outcome stratified by race after RP for early-stage prostate cancer. These studies are listed in Table 3. Four of the six studies revealed that race was not a significant predictor of PSA failure.6-11 These studies are limited because they fail to stratify patients for known clinical predictors of PSA failure. Previously published studies confirm that the pretreatment PSA level, 1992 AJCC clinical T stage, and biopsy Gleason score are independent predictors of PSA failure-free survival after RP43-45 or external-beam radiation therapy.44 Therefore, when comparing PSA outcome, it is Table 3. Fig 2. PSA failure-free (bNED) survival by race for high-risk patients (P ⴝ .28). bNED, biochrmical no evidence of disease. important to control for these factors. Two studies reported on PSA outcome between African-American and white patients with localized prostate cancer by risk groups based on PSA, clinical T stage, and Gleason score.34,35 Both of these studies included patients that had received neoadjuvant or adjuvant hormonal therapy or adjuvant radiation. In addition, whereas low-risk was defined consistently in these studies, intermediate- and high-risk definitions differed. The current study compared PSA outcome among racial groups after RP for localized prostate cancer stratified by pretreatment clinical factors into established risk groups and in the absence of adjuvant or neoadjuvant therapies. The main finding of this study was that PSA outcomes between racial groups were not significantly different for the lowand high-risk groups (P ⫽ .70 and P ⫽ .28, respectively). However, at presentation, the PSA, clinical T stage, Gleason score, and percentage of positive biopsy specimens for African-American men were significantly more advanced Studies Evaluating the Association of Race and Recurrence After RP for Clinically Localized Prostate Cancer Study Study Population/Years African-American White Statistical Significance for Racial Differences in Recurrence, (P) Moul et al, 19966 Iselin et al, 19987 Eastham et al, 20008 Powell et al, 20009 Freedland et al, 200010 Tarman et al, 200011 Cross et al, current study Walter Reed Army Med Center/1975-1995 Duke University Med Center/1970-1996 LSU Veterans Affairs Med Center/1990-1998 Wayne State University Harper Hospital/1991-1995 UCLA Veterans Affairs Med Center/1991-1999 Multiple Institutions of the Defense Department/1987-1997 Brigham Women’s and University of PA Hospitals/1989-2000 107 115 218 100 125 192 162 366 1,204 257 178 148 866 1,874 Significant, .049 Not significant, .14 Not significant, .97 Not significant, .42 Not significant, .20 Significant, .035 Not significant* Ethnic Composition *Low-risk group P, .70 and high-risk group P, .28. Downloaded from jco.ascopubs.org on June 15, 2014. For personal use only. No other uses without permission. Copyright © 2002 American Society of Clinical Oncology. All rights reserved. 2867 IMPACT OF RACE ON PSA OUTCOME compared with white men. As a result, African-American men presented with more advanced disease and at younger ages, as noted by a higher proportion of African-American men compared with white men in the high-risk group (55% v 37%, respectively) and lower proportion of AfricanAmerican men compared with white men in the low-risk group (45% v 63%, respectively). This study has limitations. First, the follow-up period may not have been long enough to see a statistical difference in PSA outcome in the low-risk group because failure can be protracted. Second, retrospective studies are not conclusive because of the possibility of unknown confounding factors that can impact results. Third, given the numerical difference, although not statistically significant in PSA outcome for high-risk patients stratified by race as shown in Fig 2, there is the possibility that a difference may emerge with a larger cohort of African-American men and longer follow-up. Despite the worse mortality rate for African-American men with prostate cancer compared with white men, this study and four others7-10 did not find race to be a significant predictor of recurrence after RP. However, African-American men with prostate cancer present at a younger age and with more advanced disease. Given that PSA outcome is not significantly different and more favorable for low-risk African-American and white individuals at 5 years, this article provides evidence to support prostate cancer screening in African-American men at a younger age. REFERENCES 1. American Cancer Society: Cancer facts and figures in 2001: Prostate cancer in minorities. Http: //www3.cancer.org/eprise/main/ docroot/stt/stt_0 2. 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