Distinct genomic differences in prostate cancer between Western countries and China

The reason why prostate cancer is significantly more common in Western than Asian men is unknown. Using a genome-wide approach to compare the genomic changes in prostate cancer tissues, we determined that those from Chinese patients lack key somatic genomic changes commonly found in Western patients, including the 21q22.2-22.3 deletion which causes the TMPRSS2:ERG fusion gene, and 10q deletion which leads to PTEN inactivation. The results were confirmed and their consequence on ERG expression was identified by study of a large series of Chinese and UK samples using tissue-microarrays. Subsequently, we identified significant AR genotype differences between UK and Chinese prostate cancer patients. The identification of specific somatic genomic differences in cancers from distinct populations may provide an opportunity to identify cancer-causing or protective factors. Copy number analysis of Affymetrix SNP 6.0 array was performed for 5 UK and 39 Chinese prostate cancer. Except 6 Chinese samples, all other samples have case-matched normal controls. Unpaired Chinese tumor samples were analyzed against a baseline from 33 Chinese normal prostate samples.