RESUMEN
INTRODUCTION: Germ cell tumours (GCTs) of the testis show exquisite sensitivity to treatment with cisplatin. Despite the high cure rates provided by platinum-based chemotherapy, 10-20% of patients die from progressive disease. Although various cellular pathways may influence cisplatin efficacy, their actual impact has not been comprehensively investigated in advanced GCTs. The objective of the present study was to clarify the role of the expression status of proteins involved in the Rb and p53 tumour suppressor pathways in sensitivity and resistance of GCTs to cisplatin-based chemotherapy. MATERIALS AND METHODS: Paraffin-embedded tumour tissues from 84 patients with advanced GCT treated with cisplatin-based chemotherapy were analysed. Immunohistochemical expression of proteins p53 and mdm2, and the G1-phase cyclins D1 and D2 (CD1 and CD2) was assessed and correlated with the clinical course. RESULTS: The percentages of positive expression of p53, mdm2, CD1 and CD2 were 56, 57, 37.5 and 55%, respectively. From univariate analysis, there was no significant association between p53, mdm2 or CD1 expression and outcome. Instead, positive CD2 expression was found to be marginally associated with shorter median duration of progression-free survival (PFS) (p=0.06). In multivariate analysis, none of the molecular markers retained statistical significance with treatment response or survival. CONCLUSIONS: Tissular expression of p53, mdm2 and CD1 is not associated with prognosis or treatment response in patients with advanced GCT. Aberrant CD2 expression appears to further determine a shorter PFS. Larger and further studies are required to validate CD2 as a marker of cisplatin resistance.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Cisplatino/administración & dosificación , Resistencia a Antineoplásicos , Neoplasias de Células Germinales y Embrionarias/tratamiento farmacológico , Neoplasias Testiculares/tratamiento farmacológico , Antígenos CD1/metabolismo , Antígenos CD2/metabolismo , Cisplatino/uso terapéutico , Supervivencia sin Enfermedad , Humanos , Inmunohistoquímica , Masculino , Neoplasias de Células Germinales y Embrionarias/metabolismo , Neoplasias de Células Germinales y Embrionarias/patología , Pronóstico , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Neoplasias Testiculares/metabolismo , Neoplasias Testiculares/patología , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
BACKGROUND: Germ 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. METHODS: One 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. RESULTS: EGFR 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 relapse-free or overall survival. CONCLUSIONS: EGFR, 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.