Abstract:

Objective To explore the efficacy of consolidation chemotherapy after radical radiotherapy and chemotherapy in stage Ⅲ-ⅣA esophageal squamous cell carcinoma （ESCC） patients in the real world. Methods The clinical data of 139 patients with stage Ⅲ-ⅣA ESCC who underwent radical radiotherapy and chemotherapy from January 1， 2018 to December 31， 2022 in Hefei Cancer Hospital， Chinese Academy of Sciences were retrospectively analyzed. Patients were divided into a control group （n=85） and a consolidation chemotherapy group （n=54） based on whether they underwent consolidation chemotherapy after radical radiotherapy and chemotherapy. The objective response rate （ORR）， disease control rate （DCR）， progression-free survival （PFS）， and overall survival （OS） between the two groups were compared. The Kaplan-Meier method was used to draw survival curves and log-rank tests were conducted. The Cox proportional risk model was used for univariate and multivariate analysis. Results The ORR of the control group and the consolidation chemotherapy group were 44.71% （38/85） and 66.67% （36/54）， respectively， with a statistically significant difference （χ²=5.54， P=0.018）； the DCR were 70.59% （60/85） and 87.04% （47/54）， respectively， with a statistically significant difference （χ²=5.04， P=0.025）. The median PFS of the two groups of patients were 9.0 and 13.1 months， respectively， with a statistically significant difference （χ²=12.74， P<0.001）； the median OS were 15.0 and 20.6 months， respectively， with a statistically significant difference （χ²=24.75， P<0.001）. The median OS of ESCC patients in two subgroups of cT_3-4N_1-3M₀ were 16.0 and 30.8 months， respectively， with a statistically significant difference （χ²=23.49， P<0.001）. Univariate analysis showed that tumor length （HR=1.57， 95%CI： 1.04-2.36， P=0.032）， objective response （HR=0.08， 95%CI： 0.04-0.17， P<0.001）， and consolidation chemotherapy （HR=0.32， 95%CI： 0.20-0.51， P<0.001） were all influencing factors for OS in ESCC patients undergoing radical radiotherapy and chemotherapy in stages Ⅲ-ⅣA. Multivariate analysis showed that tumor length （HR=1.59， 95%CI： 1.05-2.43， P=0.030）， objective response （HR=0.05， 95%CI： 0.02-0.10， P<0.001）， and consolidation chemotherapy （HR=0.22， 95%CI： 0.13-0.36， P<0.001） were all independent influencing factors for OS in stage Ⅲ-ⅣA ESCC patients undergoing radiotherapy and chemotherapy. In terms of safety， the consolidation chemotherapy group experienced 7 adverse reactions mainly gastrointestinal reaction and leukopenia， including 5 cases of grade 1-2 and 2 cases of grade 3-4； 22 cases of adverse reactions occurred in the control group including 16 cases of grade 1-2 and 6 cases of grade 3-4 mainly including neutropenia, thrombocytopenia, anemia and digestive tract reaction. The incidence rates of adverse reactions in the two groups were 12.96% （7/54） and 25.88% （22/85）， respectively， with no statistically significant difference （χ²=3.34， P=0.068）. Conclusion After radical radiotherapy and chemotherapy， consolidation chemotherapy can significantly improve the prognosis of stage Ⅲ-ⅣA ESCC patients， and the overall adverse reactions are controllable.

Key words: Esophageal squamous cell carcinoma, Chemoradiotherapy, Maintenance chemotherapy, Treatment outcome, Prognosis