Sanmamed, Miguel FEsteban, EUriol, EZarate, RCapelan, MMuriel, CCrespo, GBerros, J PPardo-Coto, PPerez, QAlvarez-Fernández, CJiménez Fonseca, PLuque, MAstudillo, A2017-05-262017-05-262017-03-20Sanmamed MF, Esteban E, Uriol E, Zarate R, Capelan M, Muriel C, et al. Epidermal growth factor receptor and epididymis invasion as prognostic biomarkers in clinical stage I testicular germ cell tumours. J Transl Med. 2017; 15(1):62.http://hdl.handle.net/10668/2662Background Inguinal orchiectomy is curative in 70–80% of clinical stage I testicular germ cell tumours (CS I TGCT). The identification of patients who are at low risk of relapse is critical to avoid unnecessary treatment. The aim of this study is to explore EGFR, hMLH-1/hMSH-2 and microsatellite instability (MSI) as potential prognostic factors of recurrence in CS I TGCT. Methods Fifty-six CS I TGCT patients who underwent inguinal orchiectomy were included in this study. We analysed the relationship between clinicopathological and molecular factors with survival. Analysis of hMLH1, hMSH2 and EGFR expression was carried out by immunohistochemistry. Methylation status of the hMLH1 promoter was determined by pyrosequencing analysis in selected cases. EGFR exons 19, 20, 21 were analysed by PCR labeled-fragments and MSI status was determined using standard Multiplex MSI assays. Results Classical pathological factors such as lymphovascular invasion, high percentage of embryonal carcinoma, rete testis invasion or tumour size ≥4 cm showed a significant relationship with a higher risk of relapse. Additionally, it was found that an epididymis invasion proved to be a significant independent poor prognostic factor of recurrence (p = 0.001). hMLH1 or hMSH2 expression showed no significant association with risk of relapse and no MSI was found. EGFR expression was observed in 30.4% of samples and its expression was associated with higher risk of relapse (HR 3.5; 95% CI 1.3–9.8; p = 0.016). None of the cases presented EGFR kinase domain mutations. Conclusions Epididymis invasion and EGFR expression, but not hMLH-1/hMSH-2 or MSI, could be potentially useful as new prognostic factors of recurrence for CS I TGCT.enTesticular germ cell tumourEGFREpididymis invarsionhMSH-2MSICarcinoma embrionarioEpidídimoExonesHumanosInmunohistoquímicaMasculinoMetilaciónInestabilidad de microsatélitesRecurrencia local de neoplasiaOrquiectomíaPronósticoRecurrenceRed TesticularNeoplasias TesticularesMedical Subject Headings::Diseases::Neoplasms::Neoplasms by Histologic Type::Neoplasms, Germ Cell and Embryonal::Carcinoma, EmbryonalMedical Subject Headings::Anatomy::Urogenital System::Genitalia::Genitalia, Male::EpididymisMedical Subject Headings::Phenomena and Processes::Genetic Phenomena::Genetic Structures::Genome::Genome Components::Genes::Gene Components::ExonsMedical Subject Headings::Organisms::Eukaryota::Animals::Chordata::Vertebrates::Mammals::Primates::Haplorhini::Catarrhini::Hominidae::HumansMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Diagnostic Techniques and Procedures::Clinical Laboratory Techniques::Histological Techniques::Histocytochemistry::ImmunohistochemistryMedical Subject Headings::Check Tags::MaleMedical Subject Headings::Phenomena and Processes::Chemical Phenomena::Chemical Processes::Biochemical Processes::Alkylation::MethylationMedical Subject Headings::Diseases::Pathological Conditions, Signs and Symptoms::Pathologic Processes::Genomic Instability::Microsatellite InstabilityMedical Subject Headings::Diseases::Neoplasms::Neoplastic Processes::Neoplasm Recurrence, LocalMedical Subject Headings::Diseases::Neoplasms::Neoplasms by Histologic Type::Neoplasms, Germ Cell and EmbryonalMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Surgical Procedures, Operative::Urogenital Surgical Procedures::Urologic Surgical Procedures::Urologic Surgical Procedures, Male::OrchiectomyMedical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::PrognosisMedical Subject Headings::Diseases::Pathological Conditions, Signs and Symptoms::Pathologic Processes::Disease Attributes::RecurrenceMedical Subject Headings::Anatomy::Urogenital System::Genitalia::Genitalia, Male::Testis::Rete TestisMedical Subject Headings::Diseases::Male Urogenital Diseases::Urogenital Neoplasms::Genital Neoplasms, Male::Testicular Neoplasmsresearch article28320414open access10.1186/s12967-017-1162-31479-5876PMC5358043