Outcomes of local thoracic surgery in patients with stage IV non–small-cell lung cancer: A SEER-based analysis

Background The outcomes of thoracic surgery for patients with stage IV non–small-cell lung cancer (NSCLC) are controversial and uncertain. Patients and methods The National Cancer Institute's Surveillance, Epidemiology, and End Results was queried for patients with stage IV NSCLC, including those treated with surgery-participated therapy modalities. Overall survival (OS) was evaluated using a variety of statistical analyses. Results The analysis was carried out for 90,982 patients from 1975 to 2016 who had been diagnosed as stage IV NSCLC. Propensity score-matched (PSM) analyses that were well-balanced with all the important confounding covariates revealed improved OS (median survival time [MST]) with patients receiving surgery versus non-surgery (MST: 15 versus 8 months, P < 0.001); undergoing surgery plus chemotherapy versus chemotherapy (MST: 19 versus 11 months, P < 0.001); and having surgery plus chemoradiation versus chemoradiation (MST: 18 versus 11 months, P < 0.001). Sequential landmark analyses for long-term survivors of ≥1 and ≥3 years all indicated improved OS (P < 0.001) on univariate and multivariate analyses for the patients receiving the three surgery-related treatment patterns listed earlier, relative to the corresponding surgery-absent treatment modalities. For synchronous presentations of varied treatment paradigms, surgical intervention significantly led to increased OS (MST, months) benefits following treatment paradigms: surgery plus chemotherapy (22), surgery plus chemoradiation (18), chemotherapy (10), surgery only (9), chemoradiation (9), surgery plus radiation (6) and radiation alone (2). The subgroup analysis demonstrated that the elevated OS associated with local thoracic surgery in addition to chemotherapy (versus chemotherapy) or chemoradiation (versus chemoradiation) fell in the subcategories of T0-3, N0-2 and 0–1 (metastatic sites) tumours. The comparison of the aforementioned two types of treatment patterns indicated that the optimal patients for the surgery were those with any combination of T1-4, N0-3, Msite0-1 and adeno- or squamous carcinoma. Conclusions The patients with T1-4, N0-3, Msite0-1 and adeno- or squamous carcinoma of stage IV NSCLC had a longer OS with local thoracic surgery in combination with chemotherapy or chemoradiation.