A Meta-analysis: The Impact Exerted By Prophylactic Cranial Irradiation (PCI) On Survival Benefits Of Patients With Extensive Stage Small Cell Lung Cancer (ES-SCLC)

Objective: Whether the ES-SCLC patients need Prophylactic Cranial Irradiation(PCI)is still controversial.Accordingly,this meta-analysis is performed to investigate the effect of PCI on survival of patients with extensive stage small cell lung cancer(ES-SCLC).Methods: To retrieve clinical studies published in PubMed,EMBASE,MEDLINE,Cochrane Library,and Web Of Science from 1977 to 2018 on the application Of prophylactic cranial irradiation in extensive stage small cell lung cancer.Literature was selected according to inclusion and exclusion criteria.The quality of included randomized controlled trials was evaluated with RevMan5.0 software traffic light diagram,and the quality of included cohort studies was evaluated with NOS scale.Statistical software Stata12.0 was used for heterogeneity test and meta-analysis.The effect index of survival data was expressed by hazard ratio(HR),the effect index of dichotomy variables was expressed by odds ratio(OR),and the range of effect quantity was expressed by 95% confidence interval(CI).The sensitivity was analyzed by the influence analysis method.Results: Finally,5 RCTs and 4 cohort studies were involved,with 1600 patients in total.Only one of the RCTs were high quality,others were middle quality.The cohort studies overall pertained to high quality.The results of sensitivity analysis indicates that the deletion of any study had no significant effect on the total combined effect.PCI can effectively extend the OS of patients carrying ES-SCLC(HR = 0.78,95% CI: 0.62 ~0.99),yet PCI had not notable effect on OS in patients carrying ES-SCLC who have taken cranial CT / MRI before PCI to exclude BM(HR = 0.81,95% CI: 0.58 ~ 1.13).PCI can effectively prolong the OS in ES-SCLC patients who were younger than 65 years old(HR = 0.71,95% CI: 0.59 ~ 0.84).PCI can effectively extend both the PFS(HR = 0.83,95% CI: 0.7 ~ 0.98)and BMFS(HR = 0.40,95% CI: 0.29 ~ 0.55)in ES-SCLC patients.Conclusion: Benefits of PCI for patients carrying ES-SCLC is still very limited though PCI can improve BMFS and PFS to a certain extent.More precise population that can benefit from PCI shall be selected.