A Systemic Review Of Efficacy And Safety Of Hyperfractionated And Conventionally Fractionated Chemoradiotherapy For Limited-stage Small Cell Lung Cancer

Background and objective:Currently,the accepted primary treatment of limited-stage small cell lung cancer(LS-SCLC)is concurrent chemoradiotherapy(CCRT),but the optimal radiotherapy for LS-SCLC is still controversial.Therefore,this systemic review,which compared the efficacy and toxicity between hyperfractionated and conventionally fractionated chemoradiotherapy,so as to provide clinicians with a reference in the selection of LS-SCLC treatment options.Methods:We used literature search strategies to perform literature searches on electronic databases such as PubMed,Web of Science,The Cochrane Library,Ovid MEDLINE,EMbase,Wanfang,CNKI,and selected the literature according to the established inclusion and exclusion criteria to collect relevant randomized controls trials(RCTs).Then we used Review Manager 5.3 and STATA 12.0 software to statistically analyze the relevant outcome indicators of the included studies to evaluate and compare the efficacy of hyperfractionated versus conventionally fractionated chemoradiotherapy for limited-stage small cell lung cancer(over survival,OS;Progression-free survival,PFS;objective response rate,ORR)and toxicity(adverse reactions,AEs).Results:This study screened 1,386 articles based on the inclusion and exclusion criteria,and eventually included 8 randomized controlled studies,including 1,716 patients.The Meta-analysis showed that the hyperfractionated chemoradiotherapy group had a higher complete response rate(RR=1.22,95%CI(1.04,1.43),P=0.02).While in the partial response(PR)(RR=1.00,95%CI(0.79,1.25),P=0.99),objective response rate(ORR)(RR=1.07,95%CI(0.94,1.23),P=0.28),there was no marked difference between the two arms.In addition,the hyperfractionated chemoradiotherapy group improved the OS of limited-stage small cell lung cancer(HR=0.87,95%CI(0.78,0.98),P=0.02).The hyperfractionated chemoradiotherapy group had a higher 1-year overall survival rate(RR=1.07,95%CI(1.01,1.13),P=0.02),2-year overall survival rate(RR=1.12,95%CI(1.01,1.24),P=0.03),4-year overall survival rate(RR=1.25,95%CI(1.05,1.49),P=0.01),and 5-year overall survival rate(RR=1.31,95%CI(1.01,1.70),P=0.04),there were statistically significant.While there was no statistically significant difference in 3-year OSR between the two groups(RR=1.10,95%CI(0.95,1.28),P=0.19).There was no marked difference between the two arms in PFS(HR=0.92,95%CI(0.79,1.06),P=0.24).In terms of toxic reactions,the results of Meta-analysis indicate that the incidence of grades 3–5radiation esophagitis(RR=1.57,95%CI(1.25,1.98),P=0.0001)and grades3–5 blood toxicity reaction(RR=1.08,95%CI(1.02,1.15),P=0.01)wasincreased in the hyperfractionated chemoradiotherapy group compared with the conventionally fractionated chemoradiotherapy group,the differences were statistically significant.The treatment-related mortality(TRM)(RR=1.34,95%CI(0.68,2.62),P=0.39)and grades 3–5radiation pneumonitis(RR=1.54,95%CI(0.96,2.47),P=0.07)were similar between the two arms.Conclusion:For LS-SCLC,the hyperfractionated chemoradiotherapy appears to be better than the conventionally fractionated radiochemotherapy,the hyperfractionated chemoradiotherapy group had higher OS,OSR and CR,which has better antitumor efficacy,but the hyperfractionated chemoradiotherapy may cause a higher incidence of adverse reactions(Grades 3-5 radiation esophagitis and hematological toxicity).More large samples and high-quality randomized controlled trials to confirm study conclusions.