ABSTRACT
OBJECTIVE: To evaluate an epigenetic assay performed on tissue from negative prostate biopsies in a group of African American (AA) men undergoing repeat biopsy, and to compare accuracy for predicting repeat biopsy outcome to prior studies conducted in predominantly Caucasian populations. MATERIALS AND METHODS: The study population consisted of 211 AA men from 7 urology centers across the United States; all of whom were undergoing 12-core transrectal ultrasound-guided repeat biopsy within 30 months from a negative index biopsy. All biopsy cores from the negative index biopsy were profiled for the epigenetic biomarkers GSTP1, APC, and RASSF1 using ConfirmMDx for Prostate Cancer (MDxHealth, Irvine, CA). RESULTS: Upon repeat biopsy, 130 of 211 subjects (62%) had no prostate cancer (PCa) detected and 81 of 211 (38%) were diagnosed with PCa. Of the subjects with PCa, 54 (67%) were diagnosed with Gleason score (GS) ≤6 PCa and 27 (33%) with GS ≥7 disease. For detection of PCa at repeat biopsy, ConfirmMDx sensitivity was 74.1% and specificity was 60.0%, equivalent to prior studies (P = .235 and .697, respectively). For detection of GS ≥7 PCa, sensitivity was 78% and specificity was 53%. The negative predictive values for detection of all PCa and GS ≥7 PCa were 78.8% and 94.2%, respectively. CONCLUSION: In this group of AA men, we successfully validated an epigenetic assay to assess the need for repeat biopsy. Results were consistent with previous studies from predominantly Caucasian populations. Therefore, the ConfirmMDx assay is a useful tool for risk stratification of AA men who had an initial negative biopsy.
Subject(s)
Biomarkers, Tumor/genetics , Black or African American , Epigenesis, Genetic , Image-Guided Biopsy/methods , Prostate/pathology , Prostatic Neoplasms/diagnosis , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Neoplasm Grading , Prognosis , Prostatic Neoplasms/ethnology , Prostatic Neoplasms/genetics , Reproducibility of Results , Retrospective Studies , United States/epidemiologyABSTRACT
PURPOSE: To compare PSA relapse-free survival (PSA-RFS) between African-American (AA) and white American (WA) males treated with permanent prostate brachytherapy (PPB) for clinically localized prostate cancer. METHODS AND MATERIALS: One thousand eighty-one consecutive patients, including 246 African-Americans, underwent PPB with 103Pd or 125I, alone or with external beam radiation therapy between September 1992 and September 1999. Computer-generated matching was performed to create two identical cohorts of WA and AA males, based on the use of neoadjuvant androgen ablation (NAAD), pretreatment PSA, and Gleason score. Presenting characteristics were used to define risk groups, as follows: Low risk had PSA