Membranous expression of Her3 is associated with a decreased survival in head and neck squamous cell carcinoma

Background: Head and neck squamous cell carcinoma (HNSCC) still remains a lethal malignancy benefiting from the identification of the new target for early detection and/or development of new therapeutic regimens based on a better understanding of the biological mechanism for treatment. The overexpression of Her2 and Her3 receptors have been identified in various solid tumors, but its prognostic relevance in HNSCC remains controversial.Methods: Three hundred eighty-seven primary HNSCCs, 20 matching metasis and 17 recurrent HNSCCs were arrayed into tissue microarrays. The relationships between Her2 and Her3 protein expression and clinicopathological parameters/survival of HNSCC patients were analyzed with immunohistochemistry.Results: Her3 is detected as either a cytoplasmic or a membranous dominant expression pattern whereas Her2 expression showed uniform membranous form. In primary tumor tissues, high membranous Her2 expression level was found in 104 (26.9%) cases while positive membranous and cytoplasmic Her3 expression was observed in 34 (8.8%) and 300 (77.5%) samples, respectively. Membranous Her2 expression was significantly associated with histological grade (P = 0.021), as grade 2 tumors showed the highest positive expression. Membranous Her3 over-expression was significantly prevalent in metastatic tissues compared to primary tumors (P = 0.003). Survival analysis indicates that membranous Her3 expression is significantly associated with worse overall survival (P = 0.027) and is an independent prognostic factor in multivariate analysis (hazard ratio, 1.51; 95% confidence interval, 1.01-2.23; P = 0.040).Conclusions: These results suggest that membranous Her3 expression is strongly associated with poor prognosis of patients with HNSCC and is a potential candidate molecule for targeted therapy.