Continuing EGFR-TKI beyond radiological progression in patients with advanced or recurrent, EGFR mutation-positive non-small-cell lung cancer: an observational study

BACKGROUND: Some patients with advanced or recurrent, epidermal growth factor receptor (EGFR) mutation-positive (EGFR M+) non-small-cell lung cancer (NSCLC) continue to receive EGFR tyrosine kinase inhibitors (TKIs) beyond radiological progression. METHODS: We analysed a cohort of 577 patients with EGFR M+ NSCLC, who had received a first-line EGFR-TKI. We classified patients according to clinical course and treatment patterns at Response Evaluation Criteria in Solid Tumors (RECIST) progressive disease (PD). We evaluated the period from RECIST PD to TKI discontinuation or clinical PD and also evaluated survival after RECIST PD and compared it between groups. RESULTS: RECIST PD was documented in 451 cases, of which 283 (62.7%) were clinically stable. 186 (65.7%) discontinued and 97 (34.3%) continued the EGFR-TKI. In those who continued EGFR-TKI, median time between RECIST PD and clinical PD or TKI discontinuation was 5.1 months. Median survival after RECIST PD in patients who discontinued and continued EGFR-TKI after clinically stable RECIST PD was 14.6 and 15.3 months (p=0.5489), respectively. In multivariate analysis, continuing EGFR-TKI therapy, female gender, better performance status and exon 19 deletion subtype were likely positive predictive factors for survival after clinically stable RECIST PD. CONCLUSION: Our study suggests that some patients could benefit from receiving an EGFR-TKI beyond radiological progression.