Abstract A86: Prostate cancer risk allele specific for African descent correlates with pathologic stage at prostatectomy

Purpose: A region on chromosome 8q24 was recently identified as a novel prostate cancer (CaP) risk locus. Inherited variation in this region is associated with CaP risk in the general population (21–58%) and specific alleles show a strong association in African American (AA) men. This study was designed to evaluate associations between 8q24 risk alleles and clinical variables, such as pathologic stage, age at diagnosis and recurrence in a case series of AA men.

Experimental Design: Peripheral blood DNA samples from 114 AA men with CaP, including 106 who had undergone radical prostatectomy (RP), were genotyped for 6 SNPs on three 8q24 regions. The presence of these SNPs was compared with clinico-pathologic and follow-up data after RP.

Results: The mean age of diagnosis and follow-up time were 57.4 years (±8.9) and 49.1 months (±31.6), respectively. Patients carrying the Broad11934905 A risk allele, which is specific for African ancestry, were more likely to have a higher pathologic stage (pT3–4) than individuals with the wild type (OR = 4.478, 95% CL: 1.418–14.140, p = 0.01068). A trend toward increased frequency of and shorter time to biochemical recurrence was noted in patients with this risk allele on Kaplan-Meier (KM) unadjusted survival analysis (p = 0.0762).

Conclusions: The Broad11934905 polymorphism at 8q24, which is only found in people of African ancestry, is associated with an increase in non-organ confined CaP at prostatectomy. Also, for those with this risk allele, there is a trend toward early biochemical recurrence that requires validation in larger studies.