Impact of Continuing First-Line EGFR Tyrosine Kinase Inhibitor Therapy Beyond RECIST Disease Progression in Patients with Advanced EGFR-Mutated Non-Small-Cell Lung Cancer (NSCLC): Retrospective GFPC 04-13 Study

Retrospective studies suggested a benefit of first-line tyrosine kinase inhibitor (TKI) treatment continuation after response evaluation in solid tumors (RECIST) progression in epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) patients. The aim of this multicenter observational retrospective study was to assess the frequency of this practice and its impact on overall survival (OS). The analysis included advanced EGFR-mutated NSCLC patients treated with first-line TKI who experienced RECIST progression between June 2010 and July 2012. Among the 123 patients included (67 +/- 12.7 years, women: 69 %, non smokers: 68 %, PS 0-1: 87 %), 40.6 % continued TKI therapy after RECIST progression. There was no difference between the patients who did and did not continue TKI therapy with respect to progression-free survival (PFS1: 10.5 versus 9.5 months, p = 0.4). Overall survival (OS) showed a non-significant trend in favor of continuing TKI therapy (33.0 vs. 21.2 months, p = 0.054). Progressions were significantly less symptomatic in the TKI continuation group than in the discontinuation group (18 % vs. 37 %, p < 0.01). Univariate analysis showed a higher risk of death among patients with PS > 1 (HR 4.33, 95 %CI: 2.21-8.47, p = 0.001), > 1 one metastatic site (HR 1.96, 95 %CI: 1.06-3.61, p = 0.02), brain metastasis (HR 1.75, 95 %CI: 1.08-2.84, p = 0.02) at diagnosis, and a trend towards a higher risk of death in cases of TKI discontinuation after progression (HR 1.62, 95 %CI: 0.98-2.67, p = 0.056 ). In multivariate analysis only PS > 1 (HR 6.27, 95 %CI: 2.97-13.25, p = 0.00001) and > 1 metastatic site (HR 2.54, 95 %CI: 1.24-5.21, p = 0.02) at diagnosis remained significant. This study suggests that under certain circumstances, first-line TKI treatment continuation after RECIST progression is an acceptable option in EGFR-mutated NSCLC patients. Clinical trial information: NCT02293733.