title: Should primary tumor be resected for non-small cell lung cancer with malignant pleural disease unexpectedly found during operation?-a systemic review and meta-analysis.
abstract: BACKGROUND
  Non-small cell lung cancer (NSCLC) with malignant pleural disease (MPD) was considered to be contraindication for surgery, but sometimes MPD was unexpectedly found intraoperatively. There was no consensus on the role of surgical intervention on the primary tumor in patients with MPD. The object of this research was to assess whether exairesis of primary tumor could prolong survival time.
  
  
  METHODS
  A systemic research of literature was performed on the databases of PubMed, Embase and Web of Science. Literatures examining surgical benefit or other prognostic factors among NSCLC patients with MPD unexpectedly found during operations were included. Hazard ratio (HR) with 95% confidence interval (95% CI) as well as P value is applied for prognostic role of surgical removal or other potential factors.
  
  
  RESULTS
  Nine articles with a total number of 861 patients fulfilled the eligibility criteria, five of them compared the survival benefit between exploration and resection among NSCLC patients with unexpected MPD, and other studies also investigated the prognostic factors in these patients. There was a significant survival benefit in patients with primary tumor resection (HR =0.443; 95% CI: 0.344-0.571; P<0.001). This role was further detected when stratified by analysis method and ethnicity. Female was an independent favorable predicted factor (HR =0.788; 95% CI: 0.648-0.959; P=0.017) while higher N-stage was a risk factor (HR =1.879; 95% CI: 1.307-2.701; P=0.001). Among patients who received primary tumor resection, higher N-stage was also a risk factor for poorer survival (HR =2.021; 95% CI: 1.496-2.730; P<0.001).
  
  
  CONCLUSIONS
  Resection of primary tumor, female and lower-N stage were suggested to be beneficial prognostic factor among NSCLC patients who were detected with MPD for the first time in the operating room. And among these people who received surgical removal of primary tumor, lower N-stage also indicated a better survival.
authors.affiliation: Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610041, China;; West China School of Medicine, Sichuan University, Chengdu 610041, China.
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610041, China;; West China School of Medicine, Sichuan University, Chengdu 610041, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Chen
authors.affiliation: West China School of Medicine, Sichuan University, Chengdu 610041, China.
authors.forename: Zihuai
authors.initials: Z
authors.lastname: Wang
authors.affiliation: West China School of Medicine, Sichuan University, Chengdu 610041, China.
authors.forename: Yingyi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Jiandong
authors.initials: J
authors.lastname: Mei
authors.affiliation: Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Chengwu
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610041, China;; Western China Collaborative Innovation Center for Early Diagnosis and Multidisciplinary Therapy of Lung Cancer, Sichuan University, Chengdu 610041, China.
authors.forename: Lunxu
authors.initials: L
authors.lastname: Liu
keywords: Surgery; malignant pleural disease (MPD); non-small cell lung cancer (NSCLC)