Abstract
BACKGROUND: In non-small cell lung cancer (NSCLC), patients with extrathoracic metastases typically have a poor prognosis, with systemic chemotherapy being the standard care. The full potential of primary resection therapy (PRT) in these patients, especially during the immunotherapy era, is not fully established. Additionally, the effectiveness of systemic preoperative therapy in this context is unclear. METHODS: This retrospective study identified NSCLC patients with extrathoracic metastases from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2019. We compared the survival rates of those treated with just chemotherapy vs those receiving both chemotherapy and PRT. RESULTS: In a study of 41 909 patients with extrathoracic metastatic NSCLC receiving chemotherapy, we found that adding PRT significantly increased overall survival (median OS post-PSM: 18 months vs 11 months, P < 0.001). However, in the immunotherapy era, its effectiveness was less pronounced (HR: 0.56 vs 0.7, P for interaction = 0.011). For patients who have metastases to multiple distant organs, combined distant organ and distant lymph node metastases, or lung metastases, no additional survival benefit from PRT was observed (all P > 0.05). Patients receiving systemic preoperative therapy before PRT had significantly better outcomes than those who did not (HR = 0.69, P < 0.001). A predictive nomogram was developed and validated, showing AUCs of 0.751 and 0.766 in the training and test sets. CONCLUSION: In both pre- and post-immunotherapy eras, patients with extrathoracic metastatic NSCLC benefit more from adding primary tumor resection to chemotherapy, especially those with preoperative systemic therapy. We created a precise nomogram to identify the best candidates for PRT among patients with extrathoracic NSCLC metastases.