P19.04 Effect of Local Therapy on Survival in Oligometastatic Epidermal Growth Factor Receptor (EGFR) Mutated Non-Small Cell Lung Cancer (NSCLC)

Abstract

To investigate for the association between local therapy and progression free (PFS) and overall survival (OS) outcomes in oligometastatic epidermal growth factor receptor (EGFR) mutated non-small cell lung cancer (NSCLC). We searched various biomedical databases for eligible studies comparing local therapy (including surgery, radiation, radiofrequency ablation) plus first line EGFR tyrosine kinase inhibitors (TKIs) versus EGFR TKIs alone in patients with oligometastatic EGFR NSCLC. We used the ROBINS-I tool to assess the methodological quality of the non-randomized studies. We reconstructed the individual patient data from the published survival curves. We used the Grambasch and Therneau test to check for the presence of non-proportional hazards. We used the accelerated time failure model with Weibul distribution to estimate the time ratios (TR) of each study and pooled them using a random effects model. We assessed the heterogeneity of the included studies using the chi-square and I2 statistics. We used the GRADE approach to assess the quality of the overall evidence. We found five non-randomized eligible studies including 632 patients. We judged all these studies to have moderate to high risk of bias in their methodological quality. We found that one of the included studies was significant for non-proportional hazards. We found that the use of local therapy was associated with 28% increase in progression free survival time (TR 1.28, 95% confidence interval (CI) 1.18 to 1.39, P < 0.001, I2 = 0%, chi-square P value = 0.44) and 34% increase in overall survival time (TR 1.34, 95% CI 1.20 to 1.48, P < 0.001, I2 = 0%, chi-square P value = 0.46). We judged the GRADE quality of the summarized evidence to be low. There were low quality evidence which demonstrated that local therapy was associated with improvement in progression free and overall survival in patients with oligometastatic EGFR NSCLC treated with first line EGFR TKI. Randomized trials are warranted to confirm these findings.