S-1 Versus S-1 Plus Cisplatin Concurrent Intensity Modulated Radiation Therapy In The Treatment Of Esophageal Carcinoma

Objective: The chemotherapy regimens for concurrent chemotherapy and radiotherapy for esophageal cancer(EC)often comprise two drugs.However,retrospective studies have reported severe toxicity for patients with EC receiving radiotherapy combined with two-drug chemotherapy.While the incidence of side effects of single-drug chemotherapy is relatively low.Therefore,we designed a phase II trial to compare the efficacy and toxicity of combining S-1 or S-1 plus cisplatin with intensity-modulated radiation therapy for EC.Methods: The patients were randomly divided into two groups according to the ratio of 1:1.They were treated with S-1 or S-1 plus cisplatin along with radiotherapy 60-66Gy/30-33 fractions.The primary outcome was endoscopic CR rate.The secondary outcomes included PFS、OS and toxicity.Results: By February 20,2019,91 patients had been enrolled.Among them,68 patients could be analyzed for safety and 54 patients could be analyzed for efficacy.There were 35 patients in the experimental group and 19 patients in the control group.In the experimental group,16 patients(45.7%)achieved complete response and 14 patients(40.0%)achieved partial response.In the control group,9 patients(47.4%)achieved complete response and 7 patients(36.8%)achieved partial response.The objective response rate(ORR)of tumors under endoscopy was similar between the two groups,with no statistical significance(P> 0.05).completion of Chemotherapy: 38 patients in the experimental group(92.7%)completed chemotherapy,while 22 patients in the control group(81.5%)completed chemotherapy(p>0.05).Completion of radiotherapy: 39 patients in the experimental group(95.1%)completed radiotherapy,while 25 patients in the control group(92.6%)completed radiotherapy(p>0.05).The incidence of grade 1,2,3 and 4 hematological toxicity in experimental group and control group was 17.1%,26.8%,4.9% and 0% VS 7.4%,40.7%,22.2% and 3.7%(p<0.05).Conclusion: The mid-term data of this trial indicate that S-1 synchronous intensity-modulated radiation therapy is no significant differences in complete response rate to S-1 combined with cisplatin synchronous intensity-modulated radiation therapy,with fewer side effects.Therefore,patients are more likely to complete treatment with S-1 synchronous intensity-modulated radiation therapy.