Title: Real world data on epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) use in advanced/metastatic non-small cell lung cancer (NSCLC) with EGFR mutations in Singapore
Abstract: Background: Treatment options for EGFR mutant advanced/metastatic NSCLC patients continue to evolve with the development of 2nd and 3rd generation EGFR TKIs. We aim to understand the use of EGFR TKI in NSCLC patients at a tertiary institution in Singapore and assess the survival of these patients. Methods: Clinical data was obtained from a prospective database, the Lung Cancer Consortium Singapore. Patients diagnosed between July 2014 and June 2017 were reviewed. Demographics and clinical characteristics of EGFR mutant advanced/metastatic NSCLC patients are presented. The type of treatment received, response and survival of these patients are analysed. Survival function was estimated by Kaplan-Meier method and differences in survival were assessed by log-rank test. A 2-sided p-value of < 0.05 was considered statistically significant. Results: There were 422 EGFR mutant NSCLC patients, and 385 (91.2%) received 1st line treatment. Amongst patients receiving 1st line treatment, 335 (88.6%) received EGFR TKI only and a further 14 (3.6%) received combined EGFR TKI and chemotherapy. Patients receiving 1st Line EGFR TKI only, combination therapy and chemotherapy only had clinical benefit (partial response and stable disease) rates of 71.0%, 85.7% and 52.8% respectively. There were 233 (60.5%) patients that received 2nd line treatment, of which 58.8% involved a switch between different generations of EGFR TKIs. Amongst patients who had 1st line EGFR TKI and went on to 2nd line EGFR TKI, there was a clinical benefit of 40.7%. Median overall survival for patients receiving 2nd line treatment is 27.6 months (95% Confidence Interval (CI), 24.2 to 30.9 months) compared to 18.5 months (95% CI, 13.9 to 23.2 months) in those receiving first line treatment only (p = <0.01). Conclusions: Majority of our EGFR mutant NSCLC patients received first line EGFR TKI treatment. However, only about 60% go on to 2nd line treatment. A switch between generations of EGFR TKI provided reasonable clinical benefit rate. Overall survival for patients receiving 2nd line treatment was better than those receiving only 1st line treatment. Legal entity responsible for the study: National Cancer Centre Singapore. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.