This study was undertaken to investigate both amplification of the epidermal growth factor receptor (EGFR) gene by fluorescence in situ hybridization and the overexpression of EGFR, Her-2/neu, CD117 (c-kit), and androgen receptor by immunohistochemical staining in a series of 11 phyllodes tumors of the prostate.
Androgen-receptor polymorphism also revealed a monoallelic X chromosome pattern in the recurrent phyllodes tumor tissue taken at autopsy, in addition to loss of heterozygosity demonstrated at locus TP53.