Abstract
BACKGROUND: Epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) develops resistance to tyrosine kinase inhibitors (TKIs). Here, we evaluated the efficacy of radiotherapy and continuation of TKIs in patients with advanced NSCLC with oligoprogression after EGFR-TKIs. METHODS: From January 2011 to January 2019, 33 patients with EGFR-mutated NSCLC on TKIs were treated by radiotherapy and continuation of TKIs for oligoprogressive disease. The primary endpoints were median progression-free survival 1 (mPFS1), mPFS2, and median overall survival (mOS). PFS1 was measured from the start of EGFR-TKIs therapy to the oligoprogression of the disease. PFS2 was measured from the date of oligoprogression to the further progression of the disease, while OS was calculated from oligoprogression to death from any cause or was censored at the last follow-up date. RESULT: The mPFS1, mPFS2, and mOS were 11.0 (95% CI, 4.4-17.6), 6.5 (95% CI, 1.4-11.6) and 21.8 (95% CI, 14.8-28.8) months, respectively. Univariate analysis showed that EGFR mutation type (p = 0.024), radiotherapy method (p = 0.001), and performance status (p = 0.017) were significantly correlated with PFS2. Univariate analysis showed that sex (p = 0.038), smoking history (p = 0.031), EGFR mutation type (p = 0.012), and radiotherapy method (p = 0.009) were significantly correlated with OS. Multivariate analysis suggested that radiotherapy method (p = 0.001) and performance status (p = 0.048) were prognostic factors for PFS2, and radiotherapy method (p = 0.040) was a prognostic factor for OS. CONCLUSION: Radiotherapy with continued TKIs is effective for EGFR-mutated NSCLC with oligoprogression, and it should be conducted as soon as possible. T790M+ patients have higher sensitivity to radiotherapy, and patients with good performance status and stereotactic body radiation therapy have better PFS2 and OS.