Prognostic outcome of treatment modalities for epidermal growth factor receptor-mutated advanced lung cancer

BACKGROUND/AIMS: The treatment of epidermal growth factor receptor (EGFR)-mutated lung cancer cases has shown remarkable development in the past two decades. However, there have been limited studies comparing the prognostic effects of EGFR-tyrosine kinase inhibitor (TKI) and other treatment modalities. Therefore, we compared the survival outcomes of patients treated with EGFR-TKIs versus those treated with other treatment modalities. METHODS: Patient data were collected from the Korean National Health Insurance Database, National Health Insurance Service-National Sample Cohort 2002 to 2015, which was released by the Korean National Health Insurance Service in 2015. The lung cancer group included patients (n = 2,003) initially diagnosed with lung cancer between January 2010 and December 2013. The main outcome was all-cause mortality. A Cox proportional hazard regression analysis was used to calculate the relative risk of mortality. RESULTS: Among the newly diagnosed lung cancer cases, 1,004 (50.1%) were included in the analysis. A 15.1-month median survival benefit was observed in the EGFR-TKI group than that of the multimodality therapy group. The risk of mortality was as follows: EGFR-TKI treatment group (n = 142; hazard ratio [HR], 5.29; 95% confidence interval [CI], 3.57 to 7.86) and multimodality therapy group (n = 326; HR, 7.42; 95% CI, 5.19 to 10.63) compared to surgery only (n = 275). CONCLUSIONS: Patients with advanced lung cancer harbouring EGFR mutations treated with EGFR-TKIs showed better median survival and lower risk of mortality than those in the multimodality therapy group. In the case of EGFR-mutated advanced lung cancer, there is room for downstaging in the TNM classification.