Abstract: Objective To investigate the expression of Excision repair cross-complementation group 6-like(ERCC6L) in non-small cell lung cancer(NSCLC),and evaluate its prognostic value.Methods From September 2016 to 2019, 144 cases of NSCLC tissues and adjacent tissues (non-tumor tissues at least 5cm away from cancerous tissues) were admitted.The expression of ERCC6L protein in NSCLC tissues and their adjacent tissues were detected using immunohistochemistry(IHC) method.The clinicopathological data of patients with high and low expression of ERCC6L were compared,and the Kaplan-Meier curves and Cox proportional hazards regression model were used to evaluate the relationship between ERCC6L expression and overall survival(OS) of NSCLC patients.Results The data of IHC staining showed that high expression of ERCC6L was detected in 42.4%(61/144) of NSCLC tissues,which was higher than in their adjacent tissues(37.7,%,37/144)(χ²=8.909,P<0.05).High expression of ERCC6L was frequently detected in poorly differentiated carcinoma(χ²=38.660,P<0.001),T2/T3 stage(χ²=6.528,P=0.011) and TNM stage Ⅲ(χ²=12.522,P<0.05).In addition,patients with high expression of ERCC6L had higher rates of lymph node metastasis(χ²=5.802,P<0.05),lymphovascular invasion(χ²=29.899,P<0.05) and pleural invasion(χ²=7.942,P<0.05) than those with low expression(P<0.05).Survival analysis revealed that patients with high expression of ERCC6L had a worse prognosis than those with low expression,and the 5-year overall survival(OS) rate of two patient groups was 44.8% and 70.5%,respectively(χ²= 15.919,P<0.05).Univariate and multivariate Cox regression analysis demonstrated that high expression of ERCC6L(HR=2.106,95%CI=1.087-4.079,P<0.05) was an independent prognostic factor for NSCLC patients.Conclusion High expression of ERCC6L is closely correlated to tumor aggressive features,and it might be a valuable prognostic biomarker for NSCLC patients.

Key words: non-small cell lung cancer;excision repair cross-complementation group 6-like;immunohistochemistry;tumor aggressive features;prognostic biomarker