Main Session
Sep
28
PQA 02 - Lung Cancer/Thoracic Malignancies, Patient Reported Outcomes/QoL/Survivorship, Pediatric Cancer
2427 - Postoperative Radiotherapy in Surgically Resected Pathologic N2 Non-Small Cell Lung Cancer Post-Chemotherapy: A Multicenter Study
Presenter(s)
Zeliang Ma, MD - Mayo Clinic Rochester, Rochester, MN
Z. Ma1, and Z. Hui2; 1Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 2Department of VIP Medical Services, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
Purpose/Objective(s):
The role of postoperative radiotherapy (PORT) in pN2 non-small cell lung cancer (NSCLC) remains debated. Two recent randomized controlled trials found that PORT reduced locoregional recurrence but did not significantly improve disease-free survival (DFS). These studies have faced criticism due to several limitations, including slow accrual leading to a reduced patient cohort, low compliance rates, limited use of intensity-modulated radiotherapy, and high rates of cardiopulmonary toxicity. To address these concerns, we conducted a large-scale, multicenter retrospective study to evaluate the potential benefits of PORT using modern radiotherapy techniques in pN2 NSCLC patients.Materials/Methods:
From four academic medical institutions, patients with pN2 NSCLC who underwent complete resection followed by four cycles of platinum-based doublet chemotherapy were included, with treatment periods spanning 2003 to 2019, depending on institutional data availability. Study endpoints included overall survival (OS), DFS, locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS). The impact of patient and treatment variables on survival outcomes was explored using Cox regression.Results:
A total of 2,120 patients were included, with a median follow-up of 55.8 months (IQR: 39.5–85.1). There were 826 patients in the PORT group and 1294 patients in the non-PORT group. In the PORT group and non-PORT group, the 5-year OS rate was 64.1% vs. 55.8% (HR, 0.74; 95%CI, 0.65 - 0.86; P < 0.01); the 5-year DFS rate was 31.1% vs. 25.7 % (HR, 0.83; 95%CI, 0.74-0.92; P < 0.01); the 5-year LRFS rate was 62.8% vs. 49.2 % (HR, 0.66; 95%CI, 0.58-0.76; P < 0.01); the 5-year DMFS rate was 32.8% (HR, 0.90; 95%CI, 0.81-1.01; P = 0.07). On multivariable analysis, PORT remained an independent predictor of improved OS, DFS, and LRFS.Conclusion:
For patients with pN2 NSCLC, PORT using modern radiotherapy techniques could improve survival by reducing locoregional recurrence.