The survival impact of concurrent chemotherapy and primary tumor radiotherapy on stage IV squamous non-small-cell lung cancer

Objective: To analyse the impact of survival with three-dimensional radiotherapy for stage IV squamous non-small cell lung cancer (NSCLC). Methods: Data for 629 eligible patients who received three-dimensional radiotherapy between 2002 and 2016 were retrospectively analyzed.161 of 183 cases were included pre-protocol. Patients received platinum-doublet chemotherapy with concurrent irradiation of the primary tumour. Primary endpoints were overall survival (OS) and progress-free survival (PFS). Results: Of 161 patients, the 1-, 2-, 3- and 5-year OS rates and median survival time (MST) were 45.7%, 14.1%, 11.2%, 2.2% and 11months, respectively. Using contrastive analysis PTV dose ≥63 Gy and <63 Gy, the 1-, 2-,3- and 5-year overall survival (OS) rates and median survival time (MST)were 48.9% vs 43.3%, 21.8% vs 8.2%, 18.4% vs 4.4%, 5.1% vs 0%, and 12 months vs 11months ( χ 2 = 7.222, P=0.007). Contrastive analysis patients received radical concurrent chemoradiation therapy, and the 1-, 2-, 3- and 5-year overall survival (OS) rates and median survival time (MST) were 54.3% vs. 37.2%, 27.2% vs. 7.5%, 24.9% vs. 4.8%, 8.3% vs. 0%, and 14 months vs. 10 months ( χ 2 = 13.180, P=0.000). Multivariate analysis showed that PTV ≥63 Gy was an independent favourable factor for survival. Conclusion: Concurrent chemotherapy and three-dimensional radiotherapy to the primary tumour in stage IV squamous NSCLC could prolong survival, and with increasing intensity of comprehensive treatment, OS gradually improved. PTV ≥63 Gy is the independent prognostic factors for OS. [Key Words] Stage IV; Squamous non-small cell lung cancer (NSCLC); Concurrent chemoradiotherapy; Overall survival