Prognostic significance of GRP78/BiP expression in patients with Stage III/IV hypopharyngeal squamous cell carcinoma

The immunoglobulin heavy chain binding protein (BiP)/glucose-regulated protein 78 (GRP78) plays an essential role in the endoplasmic reticulum (ER) stress, and GRP78/BiP is known to be highly expressed in various human neoplasms. The clinicopathological features of GRP78/BiP expression in patients with advanced hypopharyngeal squamous cell carcinoma (HSCC) remain unclear. The aim of this study is to elucidate the prognostic significance of GRP78/BiP for HSCC. A total of 68 patients with advanced HSCC (stage III/IV) were analyzed, and tumor specimens were stained with immunohistochemistry for GRP78/BiP, Ki-67, and microvessel density (MVD), as determined through CD34 and p53 levels. GRP78/BiP was highly expressed in 80.8% (55/68) of all patients. The expression level of GRP78/BiP disclosed no significant relationship with any variables. Multivariate analysis confirmed that low expression of GRP78/BiP was an independent prognostic factor for predicting poor overall survival and progression-free survival in patients with advanced HSCC. The decreasing expression of GRP78/BiP was identified as a significant predictor related to shorter survival duration after surgery for advanced HSCC. Our study suggests that the reduced expression of GRP78/BiP contributes to worse survival for patients with advanced head and neck cancer.