Clinical management and outcome of patients with advanced NSCLC carrying EGFR mutations in Spain

Abstract

Background: Although the benefit of first-line epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors (TKIs) over chemotherapy has been demonstrated in several clinical trials, data from clinical practice is lacking and the optimal EGFR TKI to be used remains unclear. This study aims to assess the real-life diagnostic and clinical management and outcome of patients with advanced non-small-cell lung cancer (NSCLC) carrying EGFR mutations in Spain. Methods: All consecutive patients recently diagnosed with advanced or metastatic NSCLC from April 2010 to December 2011 in 18 Spanish hospitals and carrying EGFR mutations were retrospectively evaluated. Results: Between March and November 2013, a total of 187 patients were enrolled (98.3% Caucasian, 61.9% female, 54.9% never-smokers, 89.0% adenocarcinoma). Mutation testing was mainly performed on biopsy tumour tissue specimens (69.0%) using a qPCR-based test (90%) (47.0% Therascreen EGFR PCR Kit). Common sensitising mutations were detected in 79.8% of patients: 57.1% had exon 19 deletions and 22.6% exon 21 L858R point mutations. The vast majority of patients received first-line therapy (n=168; 92.8%). EGFR TKIs were the most commonly used first-line treatment (81.5%), while chemotherapy was more frequently administered as a second- and third-line option (51.9% and 56.0%, respectively). Of 141 patients who experienced disease progression, 79 (56.0%) received second-line treatment. After disease progression on first-line TKIs (n=112), 33.9% received chemotherapy, 8.9% chemotherapy and a TKI, and 9.8% continued TKI therapy. Most patients received first-line gefitinib (83.0%), while erlotinib was more frequently used in the second-line setting (83.0%). Progression-free survival (PFS) and overall survival (OS) in patients harbouring common mutations were 11.1months and 20.1months respectively (exon 19 deletions: 12.4 and 21.4months; L858R: 8.3 and 14.5months), and 3.9months and 11.1months respectively for those with rare mutations. Conclusion: EGFR TKIs (gefitinib and erlotinib) are used as the preferred first-line treatment while chemotherapy is more frequently administered as a second- and third-line option in routine clinical practice in Spain. In addition, efficacy data obtained in the real-life setting seem to concur with data from EGFR TKI phase III pivotal studies in NSCLC.