Real-world survival outcomes of radiotherapy-based treatment strategies for esophageal cancer: A population-based analysis from the Hong Kong CADRS.

Abstract

e16122 Background: Radiotherapy is an essential component of treatment for esophageal cancer across definitive, perioperative, and salvage settings. However, survival outcomes associated with different radiotherapy-based strategies in real-world clinical practice remain incompletely understood. We conducted a population-based analysis to evaluate survival outcomes and prognostic factors among patients with esophageal cancer treated with radiotherapy in Hong Kong. Methods: Using the Hong Kong Clinical Data Analysis and Reporting System (CADRS), we identified patients with esophageal cancer who received radiotherapy between 2007 and 2022. Patients were categorized into three groups according to treatment strategy: definitive radiotherapy with or without chemotherapy, perioperative radiotherapy with or without chemotherapy combined with surgery, and salvage radiotherapy with or without additional surgery or chemotherapy. Overall survival (OS) was estimated using the Kaplan–Meier method and compared using the log-rank test. Prognostic factors were evaluated using univariate and multivariate Cox proportional hazards models. Results: A total of 1,926 patients were included, of whom 1,028 (53.4%) received definitive radiotherapy, 446 (23.1%) perioperative radiotherapy, and 452 (23.5%) salvage radiotherapy. The median age was 64 years, and 83.9% of patients were male. Median OS differed significantly among treatment strategies ( P < 0.001), with the longest survival observed in the perioperative radiotherapy group (20.0 months, 95% CI 16.3–24.1), followed by the definitive radiotherapy group (7.1 months, 95% CI 6.4–7.8), and the salvage radiotherapy group (3.0 months, 95% CI 2.5–3.6). In multivariate analysis, perioperative radiotherapy was independently associated with improved OS compared with definitive radiotherapy (HR 0.585, 95% CI 0.514–0.665, P < 0.001), whereas salvage radiotherapy was associated with worse OS (HR 1.568, 95% CI 1.390–1.769, P < 0.001). Concurrent chemotherapy remained independently associated with improved survival (HR 0.656, 95% CI 0.584–0.736, P < 0.001). Conclusions: In this large population-based real-world cohort, survival outcomes among patients with esophageal cancer treated with radiotherapy varied markedly according to treatment strategy. Perioperative radiotherapy was associated with the most favorable survival, while outcomes following salvage radiotherapy remained poor. These findings highlight the importance of treatment intent when interpreting real-world outcomes of radiotherapy in esophageal cancer.