Abstract
Background: Epidermal growth factor receptor (EGFR) mutated non-small cell lung cancer (NSCLC) shows an impressive initial response to EGFR tyrosine kinase inhibitors (EGFR-TKI). However, resistance invariably develops, commonly involving the site of initial gross disease. Cytoreductive stereotactic body radiotherapy (SBRT) for thoracic oligoprogressive disease (OPD) may effectively delay progression through EGFR-TKI therapy.Methods: From a prospectively maintained IRB-approved institutional registry, we identified 23 patients consecutively treated between 2011-2019 with thoracic SBRT and received EGFR-TKI within 6-months of SBRT. Radiographic progression-free (PFS) and overall survival (OS) were estimated using Kaplan-Meier analysis. Toxicity and patient-reported Edmonton Symptom Assessment Scale (ESAS) scores were reviewed.Results: Median follow-up after SBRT was 20-months (range, 4-100), and the median age was 68-years (range, 33-89). Most patients were females (n=21;91.3%). RT dose was 50-60 Gy in 5-10 fractions. EGFR-TKI administered were erlotinib, osimertinib and gefitinib in 15, 5, and 3 patients, respectively. Median PFS and OS following SBRT were 8-months and 31-months, respectively. 1-year PFS and OS were 34.8% and 78.3%. The median duration of EGFR-TKI therapy was 26-months (1-91). Most patients progressed in new distant sites, most commonly bones (n=5;21.7%) and distant lung (n=4;17.4%), with only 2/23 patients having initial progression within the SBRT field. Grade-2 pneumonitis (n=2) and rib fracture (n=1) were noted radiation-related toxicities. Dominant ESAS symptoms were fatigue (21.7%), pain (8.7%), and loss of appetite (8.7%).Conclusions: For EGFR-mutated NSCLC patients with thoracic OPD on EGFR-TKI, SBRT was well tolerated, resulted in changes in subsequent patterns of failure, lengthened PFS, and prolongs the duration of initial TKI therapy.
Evaluation of safety and efficacy of minocycline combined with tyrosine kinase inhibitors in patients of EGFR mutated metastatic lung cancer
