444P - Propensity score-matching analysis of local consolidative therapy for patients with oligometastatic non-small cell lung cancer without progression after front-line systemic therapy

Abstract

Background: The effects of local consolidative therapy (LCT) for oligometastatic non-small-cell lung cancer patients, who did not progression after front-line systemic treatment, were examined using propensity matching. Methods: We identified 127 patients in Guangdong Lung Cancer Institute (GLCI) from 2009 to 2012 with oligometastatic disease, which we defined as 3 or fewer metastatic lesions at diagnosis and stratified according to use of LCT after systemic treatment. Propensity score-matching (PSM) methods were used to balance the baseline characteristics of patients who did (n = 57) or did not (n = 57) undergo LCT and overall survival (OS) were compared between these two patient groups using Kaplan-Meier. Furthermore, independent prognostic factors were investigated in LCT group using Cox models. Results: After PSM, LCT was associated with longer survival for oligometastatic disease (27.1m vs 16.7m, HR = 0.43 [95%CI=0.25-0.57], p < 0.001). In the LCT subgroup analysis, longer OS was observed in EGFR positivity (58.3m vs 25.7m, HR = 0.40 [95%CI 0.17-0.81], p = 0.017) and node negativity (42.8m vs 25.6m, HR = 0.49 [95%CI 0.28-0.98], p = 0.047).Table: 444PClinical characteristics for patients treated with and without LCT before and after PSMclinical characteristicBefore PSMAfter PSMLCT(n = 57)Non-LCT(n = 70)PLCT(n = 57)Non-LCT(n = 57)PAge, years(range)55 (37-77)61.5 (36-88)0.02655(37-77)60 (36-88)0.246GenderMale43(75.4%)45(64.3%)0.18443(75.4%)40(70.2%)0.674Female14(24.6%)25(35.7%)14(24.6%)17(29.8%)TT19(15.8%)7(10.0%)0.7449(15.8%)7(10.3%)0.839T227(47.4%)36(51.4%)27(47.4%)31(54.4%)T313(22.8%)19(27.2%)13(22.8%)13(22.8%)T48(14.0%)8(11.4%)8(14.0%)6(10.5%)NN012(21.1%)11(15.7%)0.49212(21.1%)11(19.3%)1.000N + 45(78.9%)59(84.3%)45(78.9%)46(80.7%)Number of sites133(57.9%)55(78.6%)0.0233(57.9%)42(73.7%)0.1142-324(42.1%)15(21.4%)24(42.1%)15(26.3%) Open table in a new tab Conclusions: Local consolidative therapy could improve overall survival in oligometastastic NSCLC patients, especially in EGFR positive and N0 patients. Legal entity responsible for the study: Guangdong Lung Cancer Institute Funding: None Disclosure: All authors have declared no conflicts of interest.