title: Might radiation therapy in addition to chemotherapy improve overall survival of patients with non-oligometastatic Stage IV non-small cell lung cancer?: Secondary analysis of two prospective studies.
abstract: The role of radiation therapy in addition to chemotherapy has not been well established in non-oligometastatic Stage IV non-small cell lung cancer (NSCLC). We aimed to investigate overall survival (OS) of non-oligometastatic Stage IV NSCLC treated with chemotherapy with concurrent radiation to the primary tumor.
  
  
  
  Eligible patients were screened from two prospective studies. Oligometastatic and non-oligometastatic NSCLC were defined as having < 5 and ≥5 metastatic lesions, respectively. Prognostic factors for OS were identified by using univariate and multivariate analysis. Landmark analysis and propensity-score matching (PSM) were each performed to further adjust for confounding.
  
  
  
  A total of 274 patients were identified as the study cohort: 183 had non-oligometastatic disease. For all 274 patients, those who received a radiation dose ≥63 Gy to the primary tumor and had oligometastatic disease had better OS (P < 0.001 and P = 0.017, respectively). When patients were subdivided into those with oligometastatic or non-oligometastatic disease, a radiation dose ≥ 63 Gy remained a significant prognostic factor for better OS. For non-oligometastatic patients, multivariate analysis showed that receiving ≥63 Gy radiation, having a GTV <146 cm3, having response to chemotherapy, and having stable or increased post-treatment KPS independently predicted better OS (P = 0.018, P = 0.014, P = 0.014, and P = 0.001). After PSM in non-oligometastatic patients, a higher radiation dose (≥63 Gy) remained to be correlated with better OS. By landmark analysis, aggressive radiation (≥63 Gy) remained to be correlated with better OS in Pre-PSM cohort (P = 0.005) and Post-PSM cohort (P = 0.004).
  
  
  
  Radiation dose, primary tumor volume, response to chemotherapy and KPS after treatment are associated with OS in patients with non-oligometastatic disease; on basis of effective system chemotherapy, aggressive thoracic radiotherapy may prolong OS.
authors.affiliation: Department of Thoracic Oncology, Affiliated Hospital of Guizhou Medical University, and Guizhou Cancer Hospital, Guiyang, 550004, China.|Teaching and Research Section of Oncology, Guizhou Medical University, Guiyang, 550004, China.
authors.forename: ShengFa
authors.initials: S
authors.lastname: Su
authors.affiliation: Department of Thoracic Oncology, Affiliated Hospital of Guizhou Medical University, and Guizhou Cancer Hospital, Guiyang, 550004, China.|Teaching and Research Section of Oncology, Guizhou Medical University, Guiyang, 550004, China.
authors.forename: YinXiang
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Thoracic Oncology, Affiliated Hospital of Guizhou Medical University, and Guizhou Cancer Hospital, Guiyang, 550004, China.|Teaching and Research Section of Oncology, Guizhou Medical University, Guiyang, 550004, China.
authors.forename: WeiWei
authors.initials: W
authors.lastname: Ouyang
authors.affiliation: Department of Thoracic Oncology, Affiliated Hospital of Guizhou Medical University, and Guizhou Cancer Hospital, Guiyang, 550004, China.|Teaching and Research Section of Oncology, Guizhou Medical University, Guiyang, 550004, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Department of Thoracic Oncology, Affiliated Hospital of Guizhou Medical University, and Guizhou Cancer Hospital, Guiyang, 550004, China.|Teaching and Research Section of Oncology, Guizhou Medical University, Guiyang, 550004, China.
authors.forename: QingSong
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Thoracic Oncology, Affiliated Hospital of Guizhou Medical University, and Guizhou Cancer Hospital, Guiyang, 550004, China.|Teaching and Research Section of Oncology, Guizhou Medical University, Guiyang, 550004, China.
authors.forename: HuiQin
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Thoracic Oncology, Affiliated Hospital of Guizhou Medical University, and Guizhou Cancer Hospital, Guiyang, 550004, China.|Teaching and Research Section of Oncology, Guizhou Medical University, Guiyang, 550004, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Gansu Cancer Hospital, Lanzhou, 730050, China.
authors.forename: XiaoHu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Sichuan Cancer Hospital, Chengdu, 610041, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Fujian Provincial Cancer Hospital, Fuzhou, 350013, China.
authors.forename: JianCheng
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou, 310022, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Thoracic Oncology and State Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, China.
authors.forename: You
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Oncology, Affiliated Hospital of Zunyi Medical College, Zunyi, 563003, China.
authors.forename: YuJu
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Tissue Engineering and Stem Cell Research Center of Guizhou Medical University, Guiyang, 550004, China.
authors.forename: ZhiXu
authors.initials: Z
authors.lastname: He
authors.affiliation: Department of Thoracic Oncology, Affiliated Hospital of Guizhou Medical University, and Guizhou Cancer Hospital, Guiyang, 550004, China. lbgymaaaa@163.com.|Teaching and Research Section of Oncology, Guizhou Medical University, Guiyang, 550004, China. lbgymaaaa@163.com.
authors.forename: Bing
authors.initials: B
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
keywords: Non-oligometastase; Non-small cell lung cancer; Overall survival; Thoracic three-dimensional radiotherapy