Paclitaxel and cisplatin combined with concurrent involved-field irradiation in definitive chemoradiotherapy for locally advanced esophageal squamous cell carcinoma: a phase II clinical trial

Purpose This trial aims to explore the efficacy and safety of involved-field irradiation (IFI) combined with paclitaxel plus cisplatin as concurrent chemoradiotherapy for locally advanced esophageal squamous cell carcinoma (ESCC), under the premise of intensity-modulated radiotherapy (IMRT). Methods Enrolled patients with locally advanced ESCC were treated with definitive concurrent chemoradiotherapy. IFI was administered adopting IMRT and the total dose was 61.2 Gy delivered in 34 fractions. On the first day of radiotherapy, the patients were treated with paclitaxel and cisplatin one cycle per month for 2 cycles followed by the same regimen in consolidation chemotherapy for two cycles. The primary endpoint of the study was the 2-year locoregional recurrence-free survival (LRFS) rate, and secondary endpoints included overall survival (OS), progression-free survival (PFS), and safety. Results Between January 2018 and September 2020, 108 patients participated in the trial. 78.7% (85/108) of patients completed all 4 cycles of chemotherapy. The median follow-up of the surviving patients was 33.9 months (interquartile range, 29.2–41.1). The 2-year LRFS rate, as the primary endpoint, was 64.2%. In addition, the median PFS was 39.2 months, and 1-year and 3-year OS rates of 88.0% and 63.3%, respectively. Among the patients, out-of-field regional failure was seen in only 7 (6.5%) patients. Neutropenia grade 3 and 4 occurred in 21.3% and 37.0% of the patients, respectively. Conclusions IFI using IMRT combined with paclitaxel and cisplatin concurrent chemotherapy for locally advanced ESCC yields encouraging local control and overall survival, but high hematological toxicity. Trial registration Clinical Trials ChiCTR1800017039.