Abstract

Background and Objective The first-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have shown significant therapeutic effects on patients harboring sensitive EGFR mutations, while the mechanisms related to drug resistance have still remained elusive. This study aimed to indicate the relationship between the expression level of Wnt5a with therapeutic effects of first-generation EGFR-TKIs on lung adenocarcinoma patients harboring sensitive EGFR mutations. Methods The medical records of 75 lung adenocarcinoma patients harboring sensitive EGFR mutations, who were admitted to our hospital and received first-generation EGFR-TKIs from June 1, 2010 to December 31, 2016, were analyzed. According to the efficacy of first-generation EGFR-TKIs, patients were divided into ineffective groups (progression-free survival (PFS) <5 months) and effective groups (PFS > 26 months). Immunofluorescence staining, immunohistochemical staining and reverse transcription polymerase chain reaction (RT-PCR) methods were utilized to detect the expression level of Wnt5a in the two groups. Results Among 75 patients, 36 patients were sensitive to first-generation EGFR-TKIs (effective group) and 39 patients were resistant to first-generation EGFR-TKIs (ineffective group). The location of Wnt5a was detected by immunofluorescence staining. Immunohistochemical staining demonstrated that the expression level of Wnt5a in the ineffective group was significantly higher than that in the effective group (P=0.0216). Besides, results of RT-PCR showed that the relative expression level of Wnt5a was remarkably higher in the ineffective group than that in the effective group (P=0.0135). Conclusion The expression level of Wnt5a was found to be associated with therapeutic effects of first-generation EGFR-TKIs in lung adenocarcinoma patients harboring sensitive EGFR mutations.