title: Prophylactic cranial irradiation for patients with small-cell lung cancer: a systematic review of the literature with meta-analysis.
abstract: BACKGROUND
  Small cell lung cancer (SCLC) accounts for about 13% of all lung cancer cases. Small cell lung cancer (SCLC) accounts for about 13% of all lung cancer cases. The purpose of the present article is to assess the role of prophylactic cranial irradiation (PCI) in small cell lung cancer (SCLC) by performing a systematic review of the randomized trials published in the literature.
  
  
  METHODS
  Randomized controlled trials were identified that compared brain metastases incidence and overall survival between PCI and No PCI in patients with SCLC. Search strategies were limited to the English language and to articles published since 1997, and included: databases searched from 1997 to March 2013 -CINAHL, Embase, Medline, Web of Science, and CENTRAL. Methodological quality was assessed with the Jadad scale. The main end points were brain metastasis and survival.
  
  
  RESULTS
  The review identified 5 trials, although few were of high quality. Two trials reported the one-year incidence of brain metastasis. PCI reduced the incidence of brain metastasis in one year, with a pooled relative risk of 0.45 (95% CI, 0.35 to 0.58; P < 0.00001). Four trials described the one year survival rate. The combined result revealed a significant (P = 0.01) survival benefit in the group assigned to PCI as compared with the control group, with a pooled relative risk of 0.87 (95% CI, 0.79 to 0.97). Three trials reported the three-year survival rate. The combined result revealed a great significant (P < 0.00001) survival benefit in the PCI group as compared with the No PCI group, with a pooled relative risk of 0.87 (95% CI, 0.83 to 0.91). the Five-year survival rate was compared in four trials Compared with the No PCI group, the PCI group had a significant (P < 0.00001) survival benefit with a pooled relative risk of 0.92 (95% CI, 0.88 to 0.95).
  
  
  CONCLUSIONS
  The present systematic review indicates that PCI decreases brain metastases incidence and that PCI improves survival in SCLC patients. Prophylactic cranial irradiation should be part of standard care for all patients with small-cell lung cancer who have a response to initial chemotherapy, and it should be part of the standard treatment in future studies involving these patients.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Zhang
authors.forename: Wenjing
authors.initials: W
authors.lastname: Jiang
authors.forename: Linlin
authors.initials: L
authors.lastname: Luan
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Zheng
authors.affiliation: School of Nursing, Shandong University, Jinan 250012, China. wanggongchao@126.com.
authors.forename: Gongchao
authors.initials: G
authors.lastname: Wang
mesh_terms: D001932:Brain Neoplasms / Q000401:mortality / Q000517:prevention & control* / Q000532:radiotherapy* / Q000556:secondary; D016371:Cranial Irradiation; D006801:Humans; D016017:Odds Ratio; D011292:Premedication; D016032:Randomized Controlled Trials as Topic; D055752:Small Cell Lung Carcinoma / Q000401:mortality / Q000473:pathology*; D016896:Treatment Outcome