Conclusion
EGFR and HER2/neu may play a limited role in prostatic adenocarcinoma as they showed positive expression in a limited number of the examined tissues specifically HER2neu. The expression of non-phosphorylated ERK (mostly weak to moderate) and phosphorylated ERK (mostly moderate to strong)- was appreciated in most cases. Thus, we suggest that anti-EGFR drugs may have a limited role in the treatment of castrate-resistant prostate cancer, but anti-MEK/ERK drugs may have more promising role as a target therapy. It is recommended to perform further molecular testing to elucidate the exact mechanism and significance of these markers.
Methods
Immunohistochemistry- using tissue microarrays- for EGFR, HER2/neu, non-phosphorylated, and phosphor-ERK, was performed on tissues from 166 patients- with primary prostatic adenocarcinoma with no prior treatment-. The
Results
The prostatic tissue showed EGFR, HER2 neu, phosphorylated and non-phosphorylated ERK expression in 8.4%, 1.4%, 78.2%, and 83.4% respectively whether low (patchy) or high expression (diffuse). There were no significant correlations found between patient characteristics and expression of the tested markers. The negative immune reactivity for non-phosphorylated ERK and EGFR- was significantly correlated with high tumor stage (p values 0.03 and 0.01, respectively).