Evaluation of different treatment strategies between right-sided and left-sided pneumonectomy for stage I-IIIA non-small cell lung cancer patients

Background: This study aimed to assess the different survival outcomes of stage I-IIIA non-small cell lung cancer (NSCLC) patients who received right-sided and left-sided pneumonectomy, and to further develop the most appropriate treatment strategies. Methods: We accessed data from the Surveillance, Epidemiology, and End Results database from the United States for the present study. An innovative propensity score matching analysis was used to minimize the variance between groups. Results: For 2,683 patients who received pneumonectomy, cancer-specific survival [hazard ratio (HR) =0.863, 95% confidence interval (CI): 0.771 to 0.965, P=0.010] and overall survival (OS; HR =0.875, 95% CI: 0.793 to 0.967, P=0.008) were significantly superior in left-sided pneumonectomy patients compared with right-sided pneumonectomy patients. Cancer-specific survival (HR =0.847, 95% CI: 0.745 to 0.963, P=0.011) and OS (HR =0.858, 95% CI: 0.768 to 0.959, P=0.007) were also significantly longer with left-sided compared to right-sided pneumonectomy after matching analysis of 2,050 patients. Adjuvant therapy could significantly prolong cancer-specific survival (67 versus 51 months, HR =1.314, 95% CI: 1.093 to 1.579, P=0.004) and OS (46 versus 30 months, HR =1.458, 95% CI: 1.239 to 1.715, P<0.001) among left-sided pneumonectomy patients after the matching procedure, while adjuvant therapy did not increase cancer-specific survival for right-sided pneumonectomy patients (46 versus 42 months, HR =1.112, 95% CI: 0.933 to 1.325, P=0.236). Subgroup analysis showed that adjuvant chemotherapy could significantly improve cancer-specific survival and OS for all pneumonectomy patients. However, radiotherapy was associated with worse survival for patients with right-sided pneumonectomy. Conclusions: Pneumonectomy side can be deemed as an important factor when physicians determine the most optimal treatment strategies.