Induction immunochemotherapy followed by radiotherapy for patients with unresectable locally advanced or metastatic esophageal cancer: A propensity score-matched analysis

The study aimed to investigate the efficacy of induction immunochemotherapy before radiotherapy (RT) for patients with locally advanced or metastatic esophageal cancer.Patients with unresectable locally advanced or metastatic esophageal cancer who received induction immunochemotherapy followed by RT (ICIs + RT group) and RT alone (RT group) were retrospectively identified in two cancer centers, respectively. Propensity score matching (PSM) was used to balance the potential confounders between the two groups. Overall survival (OS), progression-free survival (PFS), and recurrence patterns were evaluated.A total of 467 patients were reviewed, and 66 were matched in each group. After PSM, the 1- and 2-year OS rates were 84.6% and 57.9% in ICIs + RT group, and 71.1% and 43.0% in RT group (HR 0.60, 95% CI 0.36-1.00, p = 0.050). The absolute increase of restricted mean survival time (RMST) for OS in ICIs + RT group compared with RT group were 0.89 years (p = 0.023) at one year and 2.59 years at two years (p = 0.030). The median PFS time, 1- and 2-year PFS rates were 20.3 months, 69.3%, and 45.7% in ICIs + RT group, and 12.2 months, 51.4%, and 35.8% in RT group (HR 0.64, 95% CI 0.41-0.99, p = 0.045). The cumulative locoregional recurrence (LRR) rate was significantly lower in ICIs + RT group (1-year rate, 17.4% vs. 38.8%, p = 0.011), and distant metastasis (DM) rates were comparable (p = 0.755). Consolidation ICIs was associated with a trend of improved 1-year OS and PFS.Induction immunochemotherapy followed by RT might improve locoregional control and survival outcomes for patients with unresectable locally advanced or metastatic esophageal cancer.