Efficacy and safety of combined treatment with pembrolizumab in patients with locally advanced or metastatic esophageal squamous cell carcinoma in the real world

Background: Treatments for patients with advanced esophageal cancer are still limited. Pembrolizumab has demonstrated antitumor activity in patients with advanced esophageal cancer in previous studies. Few studies have assessed safety and efficacy in routine clinical practice. We investigated the real-world outcomes of pembrolizumab for patients with advanced esophageal cancer. Methods: This retrospective, observational study collected 57 advanced esophageal squamous cell carcinoma (ESCC) patients from October 1, 2019 to October 1, 2021, 57 who received different patterns of treatments according to the staging were collected. Briefly, patients diagnosed with locally advanced and surgically resectable ESCC received neoadjuvant therapy followed by surgery. For patients with locally advanced, unresectable ESCC, the treatment regimen including chemoradiotherapy combined with pembrolizumab was performed. Patients with metastatic ESCC or those not suitable for radiotherapy received pembrolizumab plus chemotherapy. Safety was assessed in all treated patients. The objective response rate (ORR) was used to evaluate the efficacy. Results: The ORR was 74.1% (40/54) among all patients. The most common adverse events (AEs) were leukopenia (36.8%, 21/57), nausea (28.1%, 16/57), and thrombocytopenia (14%, 8/57). Grade III and higher AEs were observed in 9 of the 57 patients (15.8%). Conclusions: For patients with advanced ESCC, combined treatment with pembrolizumab was effective and safe. Multicenter studies should be carried out for further confirmation.