Abstract. This study was conducted to investigate the mutation status of epidermal growth factor receptor (EGFR) and its association with clinical characteristics and tumor markers in non-small-cell lung cancer (NSCLC) patients from the Xinjiang Uygur Autonomous Region in China. We enrolled 51 cases of NSCLC patients who received radical surgical treatment in the First Affiliated Hospital of Xinjiang Medical University. Quantitative polymerase chain reaction was applied to detect exons 18, 19, 20 and 21 of the EGFR gene in tumor tissues. Multiple tumor markers, including carcinoembryonic antigen (CEA), were assessed preoperatively. The EGFR-positive rate was 49.02% (25/51), with a mutation rate of 8% (2/25) in exon 18, 52% (13/51) in exon 19, 40% (10/51) in exon 21 and no mutations in exon 20. The positive mutation rate in men and women was 37.5% (12/32) and 68.42%, respectively (13/19), with a statistically significantly higher rate in women (P<0.05). There were also statistically significant differences among adenocarcinoma, adenosquamous carcinoma and squamous cell carcinoma cases (P<0.05), while no statistically significant differences were observed in adenocarcinoma cases regarding degree of differentiation, lymph node metastasis and TNM stage (P>0.05). There was a statistically significant association between the EGFR gene mutation status and the preoperative serum CEA level (P<0.05). The mutation rate of the EGFR gene was 68.42% in female lung adenocarcinoma patients, which supports the application of targeted therapy in such cases. However, whether it is possible to obtain information regarding targeted therapy through measuring the level of serum CEA for NSCLC patients with unknown EGFR mutation status requires further investigation through related studies including a higher number of cases. IntroductionLung cancer is one of the most common malignant tumors in humans, with an equally high incidence in men and in women. Approximately 80% of lung cancer cases are non-small-cell lung cancer (NSCLC) (1). The majority of the patients present with advanced-stage lung cancer at diagnosis, when radical excision is no longer feasible (2) and the remaining treatment options include radiotherapy, chemotherapy and immune therapy. The rate of response to radiotherapy and chemotherapy is only 15-35%, which may not effectively improve the survival rate and life quality of the patients. Therefore, the total 5-year survival rate of lung cancer patients is only ~15% (2-4).Over the last few years, genetic testing and targeted therapy based on epidermal growth factor receptor (EGFR) gene mutation status has attracted significant attention. Multiple clinical studies indicated that tyrosine kinase inhibitors (TKIs) have effectively extended the survival time and improved the life quality of NSCLC patients (5), with a total effectiveness rate of >70%. However, the effectiveness rate of TKI treatment for wild-type EGFR cancers is only 10-15% (6). Therefore, it is crucial to determine the mutation status of the EGFR gene in NSC...