Efficacy of adjuvant immunotherapy and immunochemotherapy in esophageal squamous cell carcinoma: A retrospective cohort study

There remains uncertainty regarding the efficacy of adjuvant immunotherapy following neoadjuvant therapy and surgery in patients with esophageal squamous cell carcinoma (ESCC). This study aimed to evaluate the prognostic value of adjuvant immunotherapy and immunochemotherapy (ICT) for ESCC patients. This retrospective cohort study reviewed ESCC patients who underwent neoadjuvant therapy followed by radical esophagectomy. Postoperative adjuvant therapy included chemotherapy, chemoradiotherapy (CRT), immunotherapy, and ICT. Overall survival (OS) and disease-free survival (DFS) were compared using the Kaplan-Meier method, and independent prognostic factors were identified via multivariate Cox regression analysis. A total of 690 patients were included, of whom 176 (25.5%) received adjuvant therapy, with 61, 37, 45, and 33 patients receiving chemotherapy, CRT, immunotherapy, and ICT, respectively. Among the adjuvant therapy group, both immunotherapy and ICT significantly improved OS compared to CRT (p < .001 and p = .011, respectively). For DFS, the immunotherapy group showed significantly better survival than the chemotherapy and CRT groups (p = .042 and p < .001, respectively). Multivariate analysis identified immunotherapy and ICT as independent favorable prognostic factors for both OS and DFS (all p < .05). Furthermore, patients receiving perioperative immunotherapy achieved superior OS and DFS than those receiving other treatment regimens (all p < .05). Our findings suggest potential benefits of immunotherapy and ICT as adjuvant therapy for ESCC. It also indicates that perioperative immunotherapy may have broader applicability beyond current recommendations and could contribute to optimizing treatment strategies.