title: Association between PD-L1 expression and driven gene status in NSCLC: A meta-analysis.
abstract: OBJECTIVE
  We explored the potential clinical association between programmed death-ligand 1 (PD-L1) expression and driven gene status in non-small cell lung cancer (NSCLC).
  
  
  METHODS
  We systemically searched through October 2015. Odd ratios (ORs) with 95% CIs were calculated to examine the association of PD-L1 expression with driven gene status. A random- or fixed-effects model was used.
  
  
  RESULTS
  Nine studies were identified. KRAS-mutant tumors were more likely to be PD-L1 positive than KRAS-wild type tumors (51% vs 36%; OR 1.69; 95% CI 1.01-2.84; p = 0.045). In contrast, PD-L1 expression did not differ by EGFR (OR 0.86; 95% CI 0.43-1.73; p = 0.675) or ALK (OR 1.02; 95% CI 0.44-2.37; p = 0.954) status. In subgroup analysis, there was also no significant association between PD-L1 expression and EGFR status in term of the cut-offs or ethnicity.
  
  
  CONCLUSIONS
  In conclusion, NSCLC with KRAS mutations showed a trend for higher frequency of positive PD-L1 expression.
authors.affiliation: Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
authors.forename: D
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. Electronic address: zhuxx01@126.com.
authors.forename: X
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Department of Cardiothoracic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
authors.forename: N
authors.initials: N
authors.lastname: Li
mesh_terms: D000077548:Anaplastic Lymphoma Kinase; D060890:B7-H1 Antigen / Q000378:metabolism*; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000378:metabolism*; D066246:ErbB Receptors / Q000235:genetics; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics
chemical_list: D060890:B7-H1 Antigen; C423236:CD274 protein, human; C117307:KRAS protein, human; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D066246:ErbB Receptors; D020794:Receptor Protein-Tyrosine Kinases; D016283:Proto-Oncogene Proteins p21(ras)
keywords: Driven genes; Meta-analysis; Non-small cell lung cancer; PD-L1