A phase II clinical trial investigating the safety and efficacy of a triple combination of radiation, chemotherapy, and immunotherapy in patients with unresectable locally advanced esophageal squamous cell carcinoma found that the therapy was effective in shrinking tumors, allowing for surgery, and significantly improving survival outcome. Additional studies are warranted to evaluate the efficacy and safety of this combination regimen, concluded Wang et al in Clinical Cancer Research.
Study Methodology
The researchers enrolled 30 patients with unresectable locally advanced esophageal squamous cell carcinoma (ESCC) into a phase II trial. The patients were between the ages of 18 and 75. They received radiation in conjunction with nab-paclitaxel plus cisplatin for 5 weeks, followed by tislelizumab plus nab-paclitaxel and cisplatin for two 21-day cycles. Patients whose tumors converted to resectable after treatment underwent surgery 2 to 4 weeks later.
The primary endpoint of the study was a 1-year progression-free survival rate.
Key Results
Of the 30 patients enrolled in the study, 5 discontinued treatment during chemoradiotherapy (CRT), and 1 patient received surgery ahead of schedule without subsequent immunotherapy. A total of 24 patients also received subsequent immunochemotherapy (iCT). Twenty patients (66.7%) achieved resectablility (R0: 95.2%; pathologic complete response: 65.0%; major pathologic response: 90.0%). The 1-year progression-free survival and overall survival rates were 79.4% and 89.6%, respectively.
The researchers found that the R0 resection group exhibited longer progression-free survival (median, not reached vs 8.4 months; hazard ratio [HR] = 0.28; 95% confidence interval [CI] = 0.08–0.84; P = .02) and overall survival (median, not reached vs 19.2 months; HR = 0.18; 95% CI = 0.04–0.73; P < .01) than patients in the nonsurgery group. Grade 3 to 4 adverse events were observed in 11 patients (36.7%), and immune-related pneumonitis was observed in 5 patients (20.8%).
Postchemoradiotherapy measurable residual disease before surgery was associated with unfavorable progression-free survival and overall survival rates.
“Our study met the primary endpoint. Conversion CRT and subsequent iCT followed by surgery was a promising treatment strategy for unresectable locally advanced ESCC,” concluded the study authors.
Yin Li, MD, senior author of this study and Director of the Section of Esophageal and Mediastinal Oncology at the Chinese Academy of Medical Sciences and Peking Union Medical College; and Nan Bi, MD, Associate Professor at the Chinese Academy of Medical Sciences and Peking Union Medical College, are the corresponding authors of this study.
Disclosure: Funding for this study was provided by the Beijing Xisike Clinical Oncology Research Foundation and Special Program for Basic Resource Survey of the Chinese Ministry of Science and Technology. For full disclosures of all study authors, visit Clinical Cancer Research.
