Local Therapy for Oligoprogressive Disease in Patients With Advanced Stage Non-small-cell Lung Cancer Harboring Epidermal Growth Factor Receptor Mutation

Introduction: The effect of local therapy (LT) for oligoprogressive epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) has not been well established. Forty-six patients with stage IIIB/IV EGFR-mutated NSCLC were treated by LT and continuing tyrosine kinase inhibitors (TKIs) for oligoprogression. The median overall survival (OS) and progression-free survival (PFS) after LT were 13.0 and 7.0 months, respectively. EGFR mutation type, sites of LT, and time from first progressive disease (PD) to LT were prognostic of OS after LT.

Purpose: Patients with advanced stage EGFR-mutated NSCLC treated with EGFR TKIs could experience oligoprogression. This study investigated the benefits of LT and continuation of TKIs for oligoprogression retrospectively.

Materials and methods: Forty-six patients with stage IIIB/IV EGFR-mutated NSCLC on TKIs were treated by LT and continuation of TKIs for oligoprogressive disease. The impact of clinicopathologic variables on survival was explored using Cox regression.

Results: With a median follow-up of 32 months, the 2-year OS was 65.2%, and the estimated OS was 35.0 months. The median OS after LT (LT-OS) was 13.0 months. The median PFS after LT (LT-PFS) was 7.0 months. Univariate analysis showed that stage at initial diagnosis, EGFR mutation type, site of LT, metastatic status at initial TKIs, and time from first PD to LT correlated with LT-OS significantly. Multivariate analysis suggested that EGFR mutation type (P = .001), sites of LT (P = .000), and time from first PD to LT (P = .034) were prognostic of LT-OS. Univariate analysis showed that metastatic status at initial TKIs and time from first PD to LT correlated with LT-PFS significantly. Multivariate analysis suggested that only time from first PD to LT (P = .000) was prognostic of LT-PFS.

Conclusion: This study revealed that LTs are feasible and effective for EGFR-mutated NSCLC with oligoprogression. EGFR mutation type, sites of LT, and time from first PD to LT were prognostic factors for LT-OS. Time from first PD to LT was a prognostic factor for LT-PFS.