OBJECTIVES: The hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (c-MET) ligand/receptor axis has been implicated in pathogenesis of malignant diseases including squamous cell carcinoma of the head and neck (SCCHN). Overexpression of c-MET has been reported as a common molecular abnormality in SCCHN, although its prognostic and predictive value remains to be validated. METHODS: We systematically searched literature for studies evaluating c-MET expression on immunohistochemistry in newly diagnosed, non-metastatic SCCHN. The c-MET expressing cases were classified into three categories according to predefined cut-off values for positivity. Our aim was to assess the prevalence of c-MET expression and its relationship with selected clinicopathological variables. RESULTS: Twenty-eight studies with 2019 cases were included. Relative frequencies of c-MET expression above cut-off levels I, II, and III were 81.8%, 63.8%, and 46.2%, respectively. Differences between these three values were statistically significant (p<1.0×10-6). Above cut-off level II, c-MET positivity was associated with worse overall survival (p=4.0×10-6), positive nodal status (p=1.0×10-4), higher disease stage (p=7.0×10-4), older age (p=2.1×10-3), disease recurrence (p=2.0×10-2), and primary tumour localization in the oral cavity (p=2.3×10-2). Above cut-off level III, c-MET positivity was associated with worse disease-free or progression-free survival (p=9.0×10-6), p16 negativity (p=2.4×10-4), worse overall survival (p=4.0×10-4), positive epidermal growth factor receptor (EGFR) status (p=7.2×10-4), and larger primary tumours (p=4.6×10-3). CONCLUSION: In SCCHN, immunohistochemical overexpression of c-MET above cut-off levels III and particularly II was associated with inferior survival outcomes and advanced disease. Moreover, it represents a promising predictive biomarker for c-MET targeting, yet the optimal scoring method remains to be defined.

AFR Oncology Boulogne Billancourt France

Department of Internal Medicine Hematology and Oncology University Hospital Brno Brno Czech Republic; School of Medicine Masaryk University Brno Czech Republic

Department of Mathematics and Statistics Faculty of Science Masaryk University Brno Czech Republic

Department of Medical Oncology Antwerp University Hospital Edegem Belgium; Faculty of Medicine and Health Sciences University of Antwerp Antwerp Belgium

Department of Oncology Bichat Beaujon University Hospital Paris France

Department of Oncology Hospital Paris Saint Joseph Paris France

School of Medicine Masaryk University Brno Czech Republic; Department of Otorhinolaryngology and Head and Neck Surgery St Anne's Faculty Hospital Brno Brno Czech Republic

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