EPIDERMAL-GROWTH-FACTOR-RECEPTOR EXPRESSION IS ASSOCIATED WITH RAPID TUMOR PROLIFERATION IN BLADDER-CANCER

Epidermal-growth-factor-receptor (EGF-r) expression has been proposed as a prognostic marker in bladder cancer and is associated with rapid proliferation in cell lines. Ninety-three fresh and 74 formalin-fixed bladder tumors were examined by fluorescence in site hybridization (FI SH) and immunohistochemistry to assess the relationship between EGF-r expression and proliferation as well as the prevalence of epidermal-gr owth-factor-receptor (EGF-r) gene amplification. EGF-r expression was strongly associated with BUdr labeling index, grade and stage. EGF-r e xpression emerged as a stronger predictor of tumor proliferation than grade or stage in analysis of variance. Rapid tumor proliferation migh t be responsible for bad prognosis reported in EGF-r positive bladder tumors. Also chromosome 7 copy number was associated with grade and st age. ECF-r gene amplification was uncommon (5 of 107 tumors). However, FISH analysis allowed characterization of the pattern of amplificatio n, with clustering of signals suggestive of intrachromosomal amplifica tion more common than diffuse distribution consistent with extrachromo somal amplification. (C) 1994 Wiley-Liss, Inc.