Definitive Chemoradiotherapy for Adenocarcinoma of the Esophagus or Esophago-Gastric Junction: A Dutch Population-Based Cohort Study.

BACKGROUND: Locally advanced esophageal adenocarcinoma has a poor prognosis and limited treatment options when surgery is not possible or desired. Although definitive chemoradiotherapy (dCRT) is currently administered as a curatively intended treatment, limited data exist regarding its efficacy for patients with adenocarcinoma of the esophagus, necessitating further evaluation of survival outcomes. METHODS: Patients with a diagnosis of adenocarcinoma of the esophagus or esophago-gastric junction who had undergone dCRT (defined as a radiation dose of > 41.4 Gy and ≤ 50.4 Gy, respectively) were identified from the nationwide Netherlands Cancer Registry (2015-2022). Overall survival (OS) was analyzed, and multivariable Cox regression analysis was performed to evaluate prognostic factors. Progression-free survival (PFS) was estimated for the subgroup of patients with detailed follow-up data from 2015 to 2017. RESULTS: The study analyzed 926 patients, including 263 patients with data on recurrence patterns. Of these patients, 77% had a diagnosis of stage III/IVa disease, and 72% had a WHO performance status of 0 to 1. The 90-day mortality rate was 7.1%. The median OS was 19.6 months (95% confidence interval [CI], 18.6-21.2 months), and the 3-year OS was 28%. The median PFS was 12.1 months (95% CI, 9.7-14.0 months). Clinical T3-T4 category, cN+ category, WHO performance status, and tumor length were linked to worse survival, although the multivariable model had limited discriminatory power. CONCLUSION: Real-world OS and PFS for patients with adenocarcinoma of the esophagus or esophago-gastric junction who received dCRT were poor, and 90-day mortality was substantial. These outcomes highlight the need for optimal patient selection, well-informed shared decision-making, and the development of improved treatment strategies.