Effect of adding immunotherapy to standard of care on survival in patients with esophageal cancer: Analysis of NCDB database.

Abstract

325 Background: Combined immuno-chemotherapy has been shown to be more effective than chemotherapy alone in advanced esophageal cancer. However, the association of immunotherapy and overall survival (OS) of patients with esophageal cancer, regardless of stage and combined therapy, is unknown. The objective is to explore the association of immunotherapy with OS in patients with all stage esophageal adenocarcinoma or squamous cell carcinoma who received any treatment. Subset analysis was conducted on OS for patients who received chemoradiation with and without immunotherapy. Methods: This study included 85,900 adult patients in the National Cancer Database diagnosed between 2004 and 2017 with stage I-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 85,900 patients, 69,264 (81%) were men, 85,159 (88%) were White and 7,875 (9%) were Black. The median (range) age at diagnosis was 64 (18-90) years. Overall, 1990 (2.3%) received immunotherapy. Immunotherapy did not improve median OS in stage I-II (31 vs 27M, p >.05) but improved median OS in stage III (from 18 to 30 M, p <.0001) and IV (from 8 to 14 M p <.0001). In the multivariable COX analysis, patients who received immunotherapy had significantly improved OS compared with no immunotherapy (HR 0.756; 95% CI 0.713-0.801; P =.001). Treatment with CRT without surgery plus immunotherapy was associated with significantly improved OS compared with CRT alone (HR 0.817; 95% CI 0.745-0.896; P =.001). Interestingly, addition of immunotherapy to CRT with surgery did not improve OS compared with CRT and surgery. After stratified by stage, immunotherapy was found to be associated with improved OS only in stage IV patients either in all patients (HR 0.685; 95% CI 0.641-0.731, p < 0.001) or in patients who received CRT without surgery (HR 0.758; 95% CI 0.682-0.841). Conclusions: In this study, the addition of immunotherapy to standard of care, especially chemoradiation without surgery was associated with improved OS compared with standard of care (or chemoradiation) alone in patients with advanced stage esophageal cancer.