Preoperative Chemoradiation Versus Postoperative Chemoradiation In Clinical Stage ?-? Esophageal Cancer:A Meta-analysis

Objective: Patients with esophageal cancer are most commonly diagnosed with clinical stage ?-? in our contry.The efficacy of surgery alone for patients with clinical stage ?-? esophageal cancer is still unsatisfactory.Plus chemoradiation is commonly pursued in patients with clinical stage ?-? disease.However,the sequence of chemoradiation and surgery in patients with clinical stage ?-? esophageal cancer remains controversial.To identify the most effective approach for clinical stage ?-? esophageal cancer,and provide theoretical basis for clinical treatment,a meta-analysis of clinical trials directly comparing preoperative chemoradiation versus postoperative chemoradiation to evaluate the effectiveness and safety of the two treatment choices in clinical stage ?-?esophageal cancer was performed.Methods: A meta-analysis was performed using trials identified through Pub Med,Embase,The Cochrane Library,Web of Science,CBM,CNKI,as well as other auxiliary retrieval,and collected all of the trials about preoperative chemoradiation versus postoperative chemoradiation in clinical stage ?-? esophageal cancer.The quality of study about randomized controlled trial(RCT)was evaluated with Cochrane quality standards,while nonrandomized clinical trials was evaluated with the Newcastle-Ottawa Scale(NOS),and statistical analysis was performed using Review Manager 5.3 software.Results: 1 RCT and 5 nonrandomized clinical trials were analyzed in the study.Metaanalysis showed that: 1-year survival rate(OR=1.24,95%CI: 0.96~1.61,P=0.09),3-year survival rate(OR=1.25,95%CI: 1.00~1.55,P=0.05),5-year survival rate(OR=1.39,95%CI: 0.93~2.06,P=0.11),surgical complication rate(OR=1.45,95%CI: 0.81~2.60,P=0.21),there were no differences between two arms.Subgroup analysis showed that: 1-year survival rate in Chinese(OR=1.20,95%CI: 0.91~1.58,P=0.20),3-year survival rate in Chinese(OR=1.14,95%CI: 0.91~1.44,P=0.26),5-year survival rate in Chinese(OR=1.33,95%CI: 0.79~2.2,P=0.28),there were no differences in Chinese.1-year survival rate in foreigners(American)(OR=1.52,95%CI: 0.80~2.88,P=0.20),5-year survival rate in foreigners(American)(OR=1.76,95%CI: 0.55~5.64,P=0.34),1,5-year survival rate in foreigners(American)were no differences.3-year survival rate in foreigners(American)(OR=2.21,95%CI: 1.20~4.07,P=0.01),P < 0.05,preoperative chemoradiation compared with postoperative chemoradiation showed a survival advantage.1-year survival rate in esophageal squamous cell carcinomas(OR=1.17,95%CI:0.87~1.57,P=0.29),3-year survival rate in esophageal squamous cell carcinomas(OR=1.07,95%CI: 0.83~1.38,P=0.60),there were no differences in esophageal squamous cell carcinomas.Conclusion: 1.The effectiveness and safety were similar between chemoradiation followed by surgery and surgery followed by chemoradiation in clinical stage ?-?esophageal cancer in Chinese,especially in esophageal squamous cell carcinomas.The sequence of chemoradiation and surgery could be individualized in clinical treatment.2.This meta-analysis showed preoperative chemoradiation may be a more effective strategy in improving survival when compared with postoperative chemoradiation in foreigners(American).3.The results should be interpreted with caution and further largescale,well-designed RCTs on this topic are still needed.