WITHDRAWN: EGFR Exon 19 Deletion is Associated with Favorable Overall Survival after First-Line Icotinib Therapy in Advanced Non-Small Cell Lung Cancer Patients: a Retrospective, Multiple-Center, Real-World Study

Background: Although previous studies demonstrated a PFS prolonging trend in NSCLC EGFR exon 19 deletion subgroup comparing with exon 21 L858R mutation subgroup treated with geftinib, erlotinib or afatinib, the efficacy of icotinib as the first-line therapy with sensitive EGFR mutation has not been elucidated.Patients and Methods: From Sept 20, 2012 to Apr 26, 2016, patients with IIIB/IV NSCLC and a confirmed EGFR exon 19 deletion or exon 21 L858R mutation receiving oral icotinib as first-line therapy were analyzed retrospectively in four cancer centers.Results: In total, 1615 Chinese patients with advanced NSCLC were screened, and 79 patients receiving icotinib in a first-line setting with intact follow-up data were enrolled.The objective response rate (ORR) was 45.57% (36/79), and the disease contral rate(DCR) reached 89.87% (71/79).The median progress free survival(PFS) and overall survival (OS) for the overall population were 13.61 months and 31.11months respectively.The median PFS was similar between the EGFR exon 19 deletion subgroup and the exon 21 mutation subgroup (12.30months vs 14.0 months, p = 0.441, HR 0.90).But the exon 19 deletion group had a significantly longer median OS than the exon 21 mutation group (34.72 months vs 28.66 months, p = 0.036, HR 0.50).Meanwhile, there was a significant difference in overall survival in the different ECOG PS subgroups (ECOG PS 0-1 vs ECOG PS 2-3, 32.59 months vs 20.59 months, p = 0.002, HR 3.09).Conclusions: EGFR exon 19 deletion is associated with favorable overall survival after first-line icotinib in advanced non small cell lung cancer patients.www.impactjournals.com/oncotarget