Expression of EGFR, HER-2/neu and KIT in germ cell tumours

BackgroundGerm cell tumours (GCTs) represent an extraordinarily chemosensitive malignancy. However, 20–30% of patients with advanced disease cannot be cured by currently available treatments. The role of tyrosine kinase receptors has been widely studied in other malignancies. Yet, limited information is available on GCTs.MethodsOne hundred and nine paraffin-embedded GCTs in 84 patients were assessed by immunohistochemistry for epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER-2)/neu and KIT (CD117) expression. Univariate and multivariate analyses were performed to evaluate their role as predictive and/or prognostic factors.ResultsEGFR and HER-2/neu staining was detected in 28% and 13% of tumours, respectively, predominantly in nonseminomatous GCTs. KIT protein was almost universally expressed in seminomas (97%), being virtually absent in choriocarcinoma and teratocarcinoma subtypes. EGFR expression showed inverse association with tumour response of borderline significance. With a median follow-up of 10.6 years, no significant association was observed between the expression of any of these markers and relapsefree or overall survival.ConclusionsEGFR, HER-2/neu and KIT have differential patterns of expression in GCTs according to histological subtypes. The expression of these markers in our series had no prognostic or predictive significance.