8q24 amplification in transitional cell carcinoma of bladder.

Genomic amplifications of the long arm of chromosome 8q are frequently detected in a number of tumor types, including neoplasias of the urothelium. DNA level amplification and increased expression of at 8q24 is commonly associated with chromosomal gains in this region. Using a urothelial cancer tissue microarray, the authors investigated the 8q24 amplification on bladder tumors and metastases. High-copy 8q24 amplification was detected in 9% (12 of 131) of primary tumors and 33% (6 of 18) of distant metastases. Additionally, the authors investigated the expression profiles of two frequently used biomarkers, p53 and Ki67, on the same arrays that had been analyzed for the 8q24 amplification. 8q24 amplification was positively correlated with Ki67 protein expression ( < 0.005), whereas a similar correlation with p53 did not reach statistical significance ( = 0.19). The authors conclude that 8q24 amplification occurs in a small subgroup of primary bladder tumors and in a more significant group of distant metastases.