Optimization of treatment options for EGFR-mutant, stage III, unresectable NSCLC: A systematic review and meta-analysis.

Abstract

8548 Background: The PACIFIC study established a new treatment standard for Stage III unresectable NSCLC, but CRT followed by durvalumab failed to bring survival benefit to patients with EGFR mutations. EGFR-TKIs have been successful in the setting of first-line treatment of advanced NSCLC and postoperative adjuvant treatment of NSCLC. We explored whether locally advanced inoperable patients with EGFR mutations can benefit from EGFR-TKIs and the possibly best treatment regimen through meta-analysis. Methods: Studies involving unresectable stage III NSCLC with EGFR mutations published in PubMed, Embase, Cochrane, ClinicalTrials.gov, and abstracts of important international conferences (ASCO, ESMO, WCLC) from January 1, 2000 to September 30, 2021 were screened. An integrative analysis was performed using STATA (version 16.0), and a network meta-analysis based on a Bayesian framework was performed using R (version 3.6.1) for the studies with a control group. The primary endpoints were progression-free survival (PFS) and overall survival (OS). Results: A total of 3291 patients were identified in 17 studies, including 5 treatment measures including concurrent chemoradiotherapy (CRT), CRT followed by durvalumab (CRT+Durva), TKI monotherapy, radiotherapy combined with TKI (RT+TKI), and CRT combined with TKI (CRT+TKI). PFS with TKI-free treatments (CRT, CRT+Durva) was significantly shorter than TKI-containing ones (TKI, RT+TKI, CRT+TKI) (HR 2.17, 95%CI 1.47-3.19), but its advantage only translated into borderline OS benefit (1.27, 0.99-1.63). In detail, the PFS with TKI-containing measures, including TKI monotherapy (0.66, 0.50-0.87), RT+TKI (0.37, 0.28-0.50), or CRT+TKI (0.14, 0.03-0.75) were all significantly longer than CRT. Furthermore, the PFS with both RT+TKI (0.40, 0.21-0.76) and CRT+TKI (0.15, 0.03-0.74) were significantly longer than CRT+Durva, while no statistical difference existed in PFS between RT+TKI and CRT+TKI. However, TKI alone had significantly shorter PFS than RT+TKI (1.78, 1.17-2.67). There was no statistical difference in OS among all the treatments, with RT+TKI ranking first in the Bayesian ranking. The integrated analysis found that RT+TKI had the longest OS (65.7 months, 55.5-76.0 months) and PFS (21.8 months, 18.0-25.7 months) and the highest response rate (77.7%, 68.8%-86.6%). Severe neutropenia was the most common with CRT+TKI, while RT+TKI brought the highest incidences of radiation pneumonitis and esophagitis. Conclusions: For EGFR mutant Stage III unresectable NSCLC, RT and TKI are both essential. RT+TKI and CRT+TKI have significantly longer PFS than CRT±immunotherapy, and RT+TKI has OS benefit trends. Due to the lack of sufficient studies on CRT+TKI, it is urgent to conduct large randomized clinical trials to explore the optimal treatment for these patients.