Epidermal growth factor receptor (EGFR) expression and KRAS mutations in penile squamous cell carcinoma: Analysis of potential application of anti-EGFR monoclonal antibodies.

Abstract

4638 Background: Penile squamous cell carcinoma (SCC) is a rare cancer with poor prognosis and limited response to conventional chemotherapy. Anti-EGFR monoclonal antibodies (mAbs) have exhibited significant anti-tumor activities in several cancers such as colorectal carcinoma, head and neck cancer. KRAS mutations are linked to a poor response to mAbs and may thereby result in resistance to anti-EGFR agents. This study was aimed to examine EGFR expression and KRAS, BRAF mutations in penile SCC and to analyze the potential application of anti-EGFR monoclonal antibodies (mAbs) for this disease. Methods: Totally 150 penile SCC specimens from patients undergone surgical resection were included. EGFR expression was evaluated by immunohistochemistry. KRAS mutations at codons 12 and 13, and the BRAF mutation at codon 600 were analyzed on DNA isolated from formalin fixed paraffin embedded tissues by direct genomic sequencing. Results: EGFR expression was positive in all specimens, and its overexpression rate was 92%. We failed to observe a significant correlation between EGFR expression and tumor grade or lymph node metastases. The detection of KRAS and BRAF mutations analysis were performed in 94 and 83 tumor tissues, respectively. KRAS mutation was detected in only one sample and no patient was found to harbor BRAF V600E point mutation. Conclusions: We found the overexpression of EGFR and the absence of KRAS and BRAF mutations in penile SCC. This suggests that anti-EGFR mAbs may be potentially considerable therapeutic agents in penile SCC.