Correlation between expression of CXCR4 and prognosis in non‐small cell lung cancer

Abstract

ABSTRACT Background and aims: CXC chemokine receptor 4 (CXCR4) is an important factor in the migration, invasiveness, metastasis and proliferation of various carcinomas. EGFR plays an important role in regulation of cell proliferation and differentiation, cell‐cell interaction and cytokine signaling. Several studies suggested that EGFR enhances the expression of CXCR4 through PI3K/Akt signal pathway. We evaluated the correlation and prognostic impact of CXCR4 and EGFR in non‐small cell lung carcinomas (squamous cell carcinoma and adenocarcinoma). Methods: Analysis of 101 cases of non‐small cell lung carcinoma was undertaken using tissue microarray technology and immunohistochemistry. Results: Moderate to strong nuclear or cytoplasmic CXCR4 expression of more than 20% of tumor cells and strong membranous EGFR expression of more than 10% of tumor cells were judged to be positive. Associations between CXCR4 and EGFR expressions and clinicopathologic features, including tumor stage, tumor size, nodal status, presence of metastasis, Ki‐67 labeling index and disease free survival (DFS) were investigated with statistical analysis. In the patients with squamous cell carcinoma, CXCR4 expression was correlated with presence of metastasis (P= 0.040) and EGFR expression was correlated with presence of metastasis (P= 0.017). But in the patients with adenocarcinoma, no statistical correlation between CXCR4 and EGFR expressions and clinicopathologic parameters was found. In the patients with squamous cell carcinoma, CXCR4 and EGFR positive groups showed significantly shorter DFS than negative groups (P= 0.033 and 0.038, respectively). Conclusions: CXCR4 expression is a significant prognostic factor in non‐small cell carcinoma, especially squmous cell carcinoma. Well designed, larger studies on CXCR4 and EGFR expressions will be needed to confirm their significances.