Abstract
BACKGROUND AND AIMS: The association of immunotherapy in combination with radiation therapy (RT) or chemoradiation with the overall survival (OS) of patients diagnosed with stage IV esophageal cancer (EC) is unknown. The aim of the current study is to explore the association of immunotherapy with OS in patients with advanced stage EC who received chemotherapy, RT, or chemoradiation. METHODS: We conducted a cohort study using the National Cancer Database and included patients diagnosed between 2013 and 2020 with stage IV esophageal adenocarcinoma or squamous cell carcinoma. The association of immunotherapy with OS was assessed with Cox proportional hazards regression, adjusted for age at diagnosis, race, sex, stage, histology, Charlson score, education, income, insurance, hospital type, place of living, region, distance to facility, year of diagnosis, and treatment modality. RESULTS: Of 18,260 patients, 2946 (17%) received immunotherapy. In the multivariable COX analysis, patients who received immunotherapy had significantly improved OS compared with no immunotherapy (hazard ratio [HR]: 0.71; 95% confidence interval [CI]: 0.67-0.75; P < .001). Chemotherapy plus immunotherapy was associated with improved OS compared to chemotherapy alone (HR: 0.69; 95% CI: 0.64-0.75; P < .001). RT plus immunotherapy was associated with improved OS compared to RT alone (HR: 0.60; 95% CI: 0.46-0.78; P < .001). Treatment with chemoradiation plus immunotherapy was associated with significantly improved OS compared with chemoradiation alone (HR 0.78; 95% CI: 0.71-0.86; P < .001). CONCLUSION: The addition of immunotherapy to chemotherapy, RT, and chemoradiation was associated with improved OS compared with chemotherapy alone, RT alone, or chemoradiation alone in patients with stage IV EC.