Accuracy and clinical influence of plasma EGFR mutation detection in management of advanced lung adenocarcinoma.

This study aimed to investigate the accuracy of plasma EGFR status detecting according to tissue EGFR status, and further explore the correlation of plasma EGFR status with clinicopathological features and progression-free survival (PFS) in patients with advanced lung adenocarcinoma. 157 patients with advanced lung adenocarcinoma were recruited. Paired tissue and plasma samples were collected before any prior treatments, EGFR gene mutation detection was performed using the amplification refractory mutation system (ARMS) method. EGFR mutations were detected in 81 tissue samples and the mutation rate was 51.6%, while in 50 plasma samples and the mutation rate was 31.8%. The overall concordance rate of EGFR mutations between tissue and plasma samples was 76.4%. And the sensitivity, specificity, positive predictive value and negative predictive value of the EGFR detection using plasma samples were 94.0%, 68.2%, 58.0 and 96.1% respectively. Patients with no-smoking (P = 0.039) and more number of metastatic sites (P = 0.012) presented a higher EGFR mutation frequency in plasma, but no association of plasma EGFR mutation with other clinicopathological features and PFS by targeted therapy was discovered. This study revealed that plasma EGFR mutation detection might be regarded as a good alternative biomarker for lung adenocarcinoma management, especially for patients who were not tolerant with obtainment of tissue samples, but further prognostic value needs to be investigated.