Comparison Of EGFR Mutation Status In Paired Pre-and Post-chemotherapy Serum For Advanced Pulmonary Adenocarcinoma

ObjectiveTo detect EGFR mutations in paired serum of pre-and post-chemotherapy from advanced pulmonary adenocarcinoma patients for evaluation of impact of chemotherapy on EGFR mutation status.MethodsMagnetic beads were used for DNA extraction from paired serum of pre-and post-chemotherapy of33advanced pulmonary adenocarcinoma patients. The EGFR exon19and21were amplified by mutant-enriched nested PCR and analyzed by denaturing high performance liquid chromatography (DHPLC) and direct sequencing.ResultsDHPLC and direct sequencing manifested high consistency in detection of EGFR mutations in serum (100%for exon19, K=1.000;93.9%for exon21, K=0.867). Direct sequencing showed superiority to DHPLC in mutation detection of exon21. EGFR mutations were detected34.4%(13/33) and54.5%(18/33) in serum of pre-and post-chemotherapy, respectively. The EGFR mutation status was consistent in45.5%(15/33) patients. Among18discordant cases,11changed from pre-chemo wild-type to post-chemo mutant-type status, while7from pre-chemo mutant-type to post-chemo wild-type status.ConclusionsDirect sequencing is superior to DHPLC using the products of mutant-enriched nested PCR for detection of EGFR mutations in serum. Chemotherapy may have influence on serum EGFR mutation status in advanced adenocacinoma patients.