Retrospective Study in Non Small Cell Lung Cancer (NSCLC) With Epidermal Growth Factor Receptor (EGFR)

The purpose of our retrospective study is to describe which circumstances EGFR TKI is continued despite progression according to the usual Response Evaluation CrIteria in Solid Tumours (RECIST) in patients with EGFR activating mutations and acquired resistance to EGFR TKI .We will collect their social and demographic data (age, sex), first Progression Free Survival ( PFS) - from start of EGFR TKI to 1st progression PFS 1- and - from first progression according to RECIST to second progression : PFS2- , Overall Survival (OS) - from diagnosis OS 1 and from first progression OS 2 -, mutational status. We will analyze more closely the mode of progression (site), the therapeutic approach at disease progression. We will define two subgroups: those for whom EGFR TKI was continued at least three months despite progression defined according to RECIST criteria, and those for whom a second-line treatment (chemotherapy without EGFR TKI) was chosen at disease progression. It will be individualized the subgroup of patients in whom it was continued TKI after progression.