Immunohistochemical GRP78 as a tumor biomarker may predict poor prognosis in patients with non-small cell lung cancers: a retrospective study

Purpose: To examine the correlation of GRP78 and GRP94 protein levels with clinicopathological variables and prognosis in primary Non-Small Cell Lung Cancer (NSCLC) patients. Methods: A total of 89 primary patients with NSCLC were included. Their surgically-resected tissues were studied by immunohistochemistry to assess GRP78 and GRP94 expression. Student's t-test, Kaplan-Meier estimator with log rank test and Cox regression analyses were performed to examine the associations of GRP78/GRP94 levels with clinicopathological variables and survival. Results: GRP78 and GRP94 expressions increased significantly in tumor samples of NSCLC patients. High GRP78 positive was associated with pathologic TNM status (p=0.003) and pathologic N status (p=0.013); while high GRP94 positive was associated with squamous-cell carcinoma subtype (p=0.001). There is no correlation between GRP78 and GRP94 levels (p =0.086). Various levels of GRP78 proteins were associated with survival of NSCLC patients (p = 0.016). A higher GRP78 level marked a shorter survival time (p = 0.043). Various levels of GRP94 proteins were not associated with survival of NSCLC patients (p = 0.610). Conclusions: High expression of GRP78 can be related to a poor prognosis. Expression level of GRP78 protein may be a potential predictor for NSCLC prognosis.