The epidermal growth factor receptor is frequently overexpressed in penile squamous cell carcinomas: a tissue microarray and digital image analysis study of 112 cases.
Disseminated penile cancer is usually treated with chemotherapy. However, response rates are far from acceptable. Recently, anti-epidermal growth factor receptor (EGFR) monoclonal antibodies have shown to be clinically useful in penile carcinomas. Nevertheless, only a few cases of penile carcinomas have been evaluated for EGFR expression. In this study, we assessed the immunohistochemical expression of EGFR in 112 patients with penile squamous cell carcinoma. We built 4 tissue microarrays and evaluated EGFR expression using a monoclonal mouse anti-EGFR antibody. For digital image analysis, we used the open-source software ImageJ version 1.47 (NIH, Bethesda, MD) along with the immunomembrane plug-in. Membranous EGFR expression was evaluated, taking into account staining completeness (0-10 points) and staining intensity (0-10 points) for a combined score (0-20 points). We classified the cases as follows: negative EGFR expression, 0 to 3 points; low EGFR expression, 4 to 8 points; and high EGFR expression, 9 to 20 points. The distribution of EGFR immunohistochemical expression was as follows: 13 cases (12%) were EGFR negative, 49 cases (44%) had low EGFR expression, and 50 cases (44%) had high EGFR expression. EGFR expression was not associated with histologic subtype (P = .47), histologic grade (P = .77), or human papillomavirus status (P = .14). In conclusion, immunohistochemical EGFR expression appears to be a common feature of penile carcinomas, independently of histologic subtype, histologic grade, and human papillomavirus presence. Whether or not EGFR expression is associated with EGFR gene mutation or if it can be used to predict response to therapy in patients with disseminated penile cancer should be evaluated in future studies.
Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD 31231, USA; Office of Scientific Research, Norte University, 1614 Asunción, Paraguay. Electronic address: alcideschaux@uninorte.edu.py.
Alcides
A
Chaux
Enrico
E
Munari
Betina
B
Katz
Rajni
R
Sharma
Kristen
K
Lecksell
Antonio L
AL
Cubilla
Arthur L
AL
Burnett
George J
GJ
Netto
D000328:Adult; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D027383:Papillomaviridae / Q000302:isolation & purification; D010412:Penile Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D046888:Tissue Array Analysis
D066246:ErbB Receptors
Digital image analysis; Epidermal growth factor receptor; Penile cancer; Squamous cell carcinomas; Targeted therapy