Epidermal growth factor receptor as an adverse survival predictor in squamous cell carcinoma of the penis

Penile carcinoma (PC) is more frequent in underdeveloped countries, generally is diagnosed at an advanced stage when therapeutic options are restricted, and thus is associated with high morbidity/mortality rates. Recent studies have demonstrated clinical benefits with epidermal growth factor receptor (EGFR)-targeted therapy in PC patients, although there is no test that provides accurate patient selection. The aim of the present study was to evaluate the prognostic value of EGFR gene and protein status in tumor samples from patients with primary penile squamous cell carcinoma (SCC). We assessed the expression of wild-type and two mutant EGFR isoforms (delA746-E750 and mL858R) by immunohistochemistry in 139 samples, of which 49 were also evaluated for EGFR copy number by fluorescence in situ hybridization (FISH). Positive immunohistochemical staining of wild-type and mutant EGFR was evidenced by complete and strong membranous staining. For FISH analysis, cases were considered unaltered, polysomic, or amplified, as determined by signals of the EGFR gene and chromosome 7. An independent cohort of 107 PC samples was evaluated for mutations in EGFR, KRAS, and BRAF. Protein overexpression was noted in nearly half of the cases and was associated with cancer recurrence (P=.004) and perineural invasion (P=.005). Expression of the two mutated EGFR isoforms was not observed. The FISH status was not associated with protein expression. Altered FISH (polysomy and gene amplification) was an independent risk factor for dying of cancer. Only one patient of 107 presented KRAS mutations, and no mutations of EGFR or BRAF were observed.

Human pathology. 2016 Nov 15 [Epub ahead of print]

Alice Muglia Thomaz da Silva Amancio, Isabela Werneck da Cunha, José Ivanildo Neves, Josiane da Silva Quetz, Dirce Maria Carraro, Rafael Malagoli Rocha, Stenio Cássio Zequi, Antonio Leopoldo Cubilla, Francisco Paulo da Fonseca, Ademar Lopes, Maria do Perpétuo Socorro Saldanha da Cunha, Marcos Venício Alves Lima, José Vassallo, Gustavo Cardoso Guimarães, Fernando Augusto Soares

Department of Anatomic Pathology, A.C. Camargo Cancer Center, São Paulo, Brazil., Department of Pathology, Cancer Institute of Ceara, Fortaleza, Brazil., Urology Division, Department of Pelvic Surgical Oncology, A.C. Camargo Cancer Center, São Paulo, Brazil., Instituto de Patologia e Investigacion, Universidad Nacional de Asuncion, Asuncion, Paraguay., Department of Urology, Cancer Institute of Ceara, Fortaleza, Brazil., Department of Anatomic Pathology, A.C. Camargo Cancer Center, São Paulo, Brazil; Laboratory of Molecular and Investigative Pathology, CIPED, State University of Campinas Medical School, Campinas, Brazil., Department of Anatomic Pathology, A.C. Camargo Cancer Center, São Paulo, Brazil; General Pathology, Faculty of Dentistry, University of São Paulo, São Paulo, Brazil. Electronic address: .