Treatment Patterns, Testing Practices, and Outcomes in Patients with EGFR Mutation-Positive Advanced Non-Small-Cell Lung Cancer in Poland: A Descriptive Analysis of National, Multicenter, Real-World Data from the REFLECT Study.

Non-small-cell lung cancer (NSCLC) represents 85% of new cases of lung cancer. Over the past two decades, treatment of patients with NSCLC has evolved from the empiric use of chemotherapy to more advanced targeted therapy dedicated to patients with an epidermal growth factor receptor () mutation. The multinational REFLECT study analyzed treatment patterns, outcomes, and testing practices among patients with -mutated advanced NSCLC receiving first-line EGFR tyrosine kinase inhibitor (TKI) therapy across Europe and Israel. The aim of this study is to describe the Polish population of patients from the REFLECT study, focusing on treatment patterns and T790M mutation testing practice. A descriptive, retrospective, non-interventional, medical record-based analysis was performed on the Polish population of patients with locally advanced or metastatic NSCLC with mutations from the REFLECT study (NCT04031898). A medical chart review with data collection was conducted from May to December 2019.The study involved 110 patients. Afatinib was used as the first-line EGFR-TKI therapy in 45 (40.9%) patients, erlotinib in 41 (37.3%), and gefitinib in 24 (21.8%) patients. The first-line EGFR-TKI therapy was discontinued in 90 (81.8%) patients. The median progression-free survival (PFS) on first-line EGFR-TKI therapy was 12.9 months (95% CI 10.3-15.4). A total of 54 patients started second-line therapy, of whom osimertinib was administered to 31 (57.4%). Among 85 patients progressing on first-line EGFR-TKI therapy, 58 (68.2%) were tested for the T790M mutation. Positive results for the T790M mutation were obtained from 31 (53.4%) tested patients, all of whom received osimertinib in the next lines of therapy. The median overall survival (OS) from the start of first-line EGFR-TKI therapy was 26.2 months (95% CI 18.0-29.7). Among patients with brain metastases, the median OS from the first diagnosis of brain metastases was 15.5 months (95% CI 9.9-18.0). The results of the Polish population from the REFLECT study highlight the need for effective treatment of patients with advanced -mutated NSCLC. Nearly one-third of patients with disease progression after first-line EGFR-TKI therapy were not tested for the T790M mutation and did not have the opportunity to receive effective treatment. The presence of brain metastases was a negative prognostic factor.