3692 - Optimal Combination of Immunotherapy-Based Treatment in Unresectable Stage III Non-Small Cell Lung Cancer Treated with Definitive Chemoradiotherapy: A Multicenter, Retrospective Real-World Study
Presenter(s)
S. Zheng1,2, C. Sun3, H. Zhang4, M. Chen2,5, and Q. Li2,6; 1Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center, Cuangzhou, China, 2United Laboratory of Frontier Radiotherapy Technology of Sun Yat-sen University & Chinese Academy of Sciences Ion Medical Technology Co., Ltd, Guangzhou, China, 3Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center, Guangzhou, China, 4Department of Radiation Oncology,Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, 5Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China, 6Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, China
Purpose/Objective(s):
Consolidation immune checkpoint inhibitors (ICIs) have become the standard therapy for unresectable stage III non-small cell lung cancer (NSCLC) after definitive chemoradiotherapy (CRT). The optimal combination of ICIs and CRT remains unknown.Materials/Methods:
In this multicenter, retrospective study, we used real-world data to compare outcomes among stage III NSCLC patients from 2018 to 2022, who received induction immunochemotherapy before CRT and followed by consolidation immunotherapy (I-CRT-I), CRT followed by consolidation immunotherapy (CRT-I), or induction immunochemotherapy before CRT (I-CRT). Survival outcomes were estimated using the Kaplan-Meier method, and multivariable Cox proportional hazards models were employed.Results:
Of 281 patients undergoing CRT and ICIs were analyzed with a median follow-up of 29.4 months. Among them, 98 patients received I-CRT-I, 62 received CRT-I, and 121 were in the I-CRT group. There was no significant difference in overall survival (OS) between the I-CRT-I group and CRT-I group (P=0.115), while landmark analysis demonstrated that OS after 24 months in the I-CRT-I group had been significantly improved compared with the CRT-I group (P=0.006). Patients in the I-CRT-I group had a significantly longer OS compared to those in the I-CRT group (P=0.004). The median progression-free survival (PFS) in the I-CRT-I group was numerically higher at 36.7 months, as compared to 20.8 months in the CRT-I group and 19.4 months in the I-CRT group. Multivariate analysis showed that I-CRT-I was a more favorable regimen for OS. Additionally, we found that patients whose time interval from treatment to radiotherapy exceeded three months, whose tumor response before radiotherapy was partial response, had improved OS in the I-CRT-I group compared to those in the CRT-I group.Conclusion:
For patients with unresectable stage III NSCLC receiving definitive CRT, induction immunochemotherapy followed by consolidation ICIs improved survival in real-world practice. This treatment strategy warrants further research.