Novel gene alteration associates with aggressive prostate cancer in African American men

The genes studied were those associated with early stages of prostate cancer development and progression. In African American men with rapid disease progression, researchers, co-led by Drs. Shiv Srivastava (USU), Albert Dobi (USU) and Matthew Freedman (DFCI), noted that a tumor suppressor gene, LSAMP, was missing from a key chromosome. The authors contend that this might, in part, explain some of the more aggressive cancers seen in African American men. In contrast, Caucasian men with similar types of prostate cancers showed much lower frequency of LSAMP alterations but higher frequency of two widely studied prostate cancer driver genes, ERG and PTEN.

The USU, Walter Reed-Bethesda and JPC collaborative team, through comprehensive evaluations of matched cohorts of African American and Caucasian American prostate cancers, previously established a higher frequency of ERG alterations in Caucasians (50-70%) and its significantly lower frequency in African Americans (20-25%). These intriguing observations actually provided the rational for the current study focusing on whole genome evaluations of prostate cancers from these two patient populations.

These findings reveal differentially distributed somatic mutations in prostate cancer across ancestral groups, and affirms the need for future evaluations of cancer genomes in global context with important implications for precision medicine strategies.

"This highly collaborative study was made possible due to complementary expertise of investigators from different institutions. Equally significant were long-term biospecimen banks and multi-center database of the Center for Prostate Disease Research (CPDR) at USU and Walter Reed-Bethesda that comprises a high proportion (25%) of African American men treated for prostate cancer in the equal access Military Healthcare System. The new emerging knowledge on ethnicity-associated differences of the prostate cancer genome and perhaps other cancers needs more research and has promising potential to enhance the repertoire of new biomarkers and therapeutic targets that may benefit all patients," said Srivastava. "Given the recent availability of next-generation sequencing opportunities at USU, we will be able to accelerate our research in this direction."