ESTRO 2025 - Abstract Book

S1852

Clinical – Upper GI

ESTRO 2025

4014

Digital Poster Patterns of Failure after Radical Chemoradiotherapy in Esophageal Squamous Cell Carcinoma: The Experience of a Center. Luísa Samarão 1 , Dora Gomes 1 , Bárbara de Castro 1 , Teresa Monjardino 2 , Olga Sousa 1 1 Radiation Oncology, Portuguese Oncology Institute of Porto, Porto, Portugal. 2 Epidemiology, Outcomes, Economics and Management in Oncology Group, Portuguese Oncology Institute of Porto, Porto, Portugal

Purpose/Objective: Characterize the patterns of failure in Esophageal Squamous Cell Carcinoma (ESCC) treated with Radical Chemoradiotherapy (RCC) in a cohort of patients.

Material/Methods: Retrospective study of patients diagnosed with ESCC consecutively treated with RCC at our institution between January 2013 and December 2022. Clinical-pathological data, treatment-related information, and oncological outcomes were analyzed descriptively. Diagnostic imaging of locoregional progression was compared with treatment volumes to correlate the type of progression with the treated area. Survival curves were analyzed using the Kaplan-Meier method. Results: A total of 139 patients were analyzed, 94% were male. Median age was 61 years (range 34–82). Most patients (93%) had a performance status ≤ 1, and the median Charlson comorbidity index was 4 (range 2–9). All patients underwent 18F-FDG PET imaging. The clinical staging distribution was: 3% stage I, 19% stage II, 59% stage III and 19% stage IVA. Positive lymph nodes were present in 86% of cases. The most common tumor location was the upper thoracic (32%) and middle thoracic (29%). The radiotherapy dose ranged between 50–54 Gy, with dose escalation to 54 Gy in cases of bulky disease (35%); 81% of patients were treated using VMAT/IMRT techniques. The most common concomitant chemotherapy regime was cisplatin/5-FU in 82% of patients, followed by carboplatin/paclitaxel in 17%, and carboplatin/5-FU (1%). Induction chemotherapy was performed in 14 patients (10%), and approximately 17% of patients did not complete the initially planned chemotherapy cycles. The median follow-up was 25 months. The cohort’s median overall survival (OS) was 26 months (95% CI: 22–35 months), with a median progression-free survival (PFS) of 20 months (95% CI: 13–60 months). Disease progression was documented in 75 patients (54%), with 55 patients (40%) experiencing locoregional progression, 40 patients (29%) having distant progression, and 20 patients (14%) presenting with both locoregional and distant progression. Locoregional progression was the most frequent failure pattern, occurring predominantly within the treatment volume (80%). Disease progression occurred mainly on the first 12 months (52 patients, 37 %), mainly locoregional (55%). Among patients with progression, 53% underwent palliative chemotherapy, 37% symptomatic care, and 7% salvage surgery. Conclusion: Esophageal tumors continue to have unfavorable clinical outcomes. In our cohort, as described in the literature, the most frequent failure pattern was locoregional. Clinical trials involving novel treatment combinations and improvement of personalized medicine are needed to better tailor treatments and, consequently, improve oncological outcomes.

Keywords: Esophageal Carcinoma; Radical Chemoradiotherapy

References: Minsky, B. D. (2002). INT 0123 (RTOG 94-05) phase III trial of combined-modality therapy for esophageal cancer: High-dose versus standard-dose radiation therapy. Journal of Clinical Oncology , 20 (5), 1167–1174. https://doi.org/10.1200/jco.20.5.1167 ;