The utility of malignant pleural effusion (MPE) as a source of tissue for determining EGFRmutations to guide EGFR TKI therapy in advanced adenocarcinoma of the lung (LUAD) remains unclear. This study compared MPE, plasma and tumor as sources of tissue for EFGR mutational analysis in LUAD patients.
MPE samples were collected from 295 LUAD patients. Matched tissue and plasma samples were available for 92 patients, and 248 patients had plasma samples. EGFRexon 19-deletion and exon 21-L858R mutation were detected. The concordance of EGFR mutation status in MPE, tissue, and plasma were evaluated, and the predictive value of EGFRmutations in MPE with respect to efficacy of EGFR-TKI was investigated.
The EGFRmutation rate in MPE samples was 39.3% (116/295). The concordance between MPEs and tissues was 87.1% (Kappa=0.712); the sensitivity and specificity of EGFRmutation in MPEs according to tissues was 71.4% and 96.5%,, respectively. 219 patients received EGFR-TKI, and the objective response rate of patients with EGFRmutations was similar for patients with EGFRmutation either in MPE, tissues or plasma (57.6 % vs 56.0 % vs 47.4%, p = 0.51). Similar results were found in progression free survival (8.9 months vs 9.0 months vs 7.7 months, p = 0.077 and overall survival (29.8 months vs 25.9 months vs 25.3 months, p = 0.33).
MPE is a reliable surrogate for tumor tissue for identifying EGFRmutations. MPE could offer reference of EGFRmutation to EGFR-TKIs treatment decision for advanced LUAD patients even when tissue and plasma were available.
Clinical trial identification
Legal entity responsible for the study
Peking University Cancer Hospital.
Has not received any funding.
All authors have declared no conflicts of interest.