Comparison of EGFR mutation between supernatant and pellets of malignant pleural effusion from patients with advanced non-small cell lung cancer / 国际肿瘤学杂志

ABSTRACT

Objective To compare the epidermal growth factor receptor (EGFR) mutation differences between supernatant and pellets of malignant pleural effusion (MPE) in advanced non-small cell lung cancer (NSCLC) patients and provide the evidence for clinical accurate detection.Methods A total of 386 consecutive MPE specimens were collected in the study (202 in experimental group and 184 in validation group).Specimens in experimental group were divided into 4 groups depending on tumors cell concentration in the sampleszero cell (n =77),(1-5) × 104/ml cells (n =43),(6-10) × 104/ml cells (n =52) and ＞ 10 × 104/ml cells group (n =30).Amplification refractory mutation system (ARMS) was performed to detect EGFR gene mutation in supernatant and pellets of each individual case respectively,and the EGFR mutation positive rates were compared between the two groups.EGFR mutation test was carried out using either supematant or pellets in validation group to verify the established method.Results In the experimental group,the total EGFR mutation positive rate was 30.7％ (62/202).In the zero cell group,EGFR mutation positive rate was higher in supernatant than that in pellets (37.6％ vs.33.8％).In the (1-5) × 104/ml cells group and (6-10) × 104/ml cells group,EGFR mutation positive rate was equal but not concordant between supematant and pellets (25.6％ and 21.1％ respectively).In the ＞ 10 × 104/ml cells group,EGFR mutation positive rate was equal (33.3％) with 100％ concordance between supernatant and pellets.In the validation group (n =184),EGFR mutation rate was 32.7％ (36/110) in supernatant and 32.4％ (24/74) in pellets,and there was no statistical significance (x2 =0.02,P =0.97).Conclusion Tumor cell free MPE specimens from patients with advanced NSCLC are suitable for EGFR mutation test.Heterogeneity of MPE results in difference with respect to EGFR gene mutation status between cell-free supernatant and pellet.Pathological evaluation based on the quantity and quality of tumor cells in MPE patients prior to test and optional samples selection are necessary to increase EGFR mutation positive rate.