Overexpression of interleukin-8 receptor 2 (IL-8R2) indicates better prognosis in esophageal adenocarcinoma and squamous cell carcinoma procession

Researches have showed that interleukin family or receptors play a role in many human tumor progressions including esophageal carcinoma. In this study, we examined the expression of interleukin-8 receptor 2 (IL-8R2) and analyze the relationship between it and esophageal carcinoma clinical characteristics. IL-8R2 protein expression was confirmed by immunohistochemistry and immunofluorescence arrays and was analyzed further via Western blot and qRT-PCR analysis in frozen tissues. The correlation between their expression levels and clinical characteristics were evaluated by Mann–Whitney and Kruskal–Wallis test. Via Kaplan–Meier plots and Cox proportional hazard models, overall survival (OS) was analyzed. Compared with normal esophageal tissue, IL-8R2 protein was overexpressed significantly in esophageal cancer (p < 0.05) and was observed both in cytoplasm and nuclear. The lower expression of IL-8R2 protein was observed with higher p staging of esophageal cancer, and the significant association between them was confirmed (p = 0.000), and in advanced p T stage, the similar result was obtained (p = 0.015); however, compared with lymph node metastasis-negative group, it is no significant difference in positive group (p = 0.152). In a Kaplan–Meier analysis, compared with IL-8R2 low expression, IL-8R2 high expression identified a group of patients with the longest OS. Cox proportional hazard models revealed that IL-8R2 predicted long time to OS. The higher expression of IL-8R2 was found in early esophageal carcinoma, which may indicate that IL-8R2 plays an important role and is better prognostic factor in esophageal cancer development.