ESTRO 2025 - Abstract Book

S1812

Clinical – Upper GI

ESTRO 2025

3000

Digital Poster Survival and Patterns of Failure in Oligometastatic Esophagogastric Cancer Orly Yariv 1 , Lara Hilal 1 , Geoffrey Y Ku 2 , Daniela Molena 3 , Yelena Y Janjigian 2 , David H Ilson 2 , Steve Maron 2 , Smita Sihag 3 , Vivian E Strong 4 , Christopher H Crane 1 , Daniel R Gomez 1 , Abraham J Wu 1 1 Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, USA. 2 Oncology, Memorial Sloan Kettering Cancer Center, New York, USA. 3 Thoracic Surgery Service, Memorial Sloan Kettering Cancer Center, New York, USA. 4 Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, USA Purpose/Objective: Metastatic esophagogastric cancer (EGC) has poor outcomes, with median overall survival (OS) of 9-11 months. Studies in other sites such as lung have shown improved survival with local treatment for oligometastases. However, limited data exists on oligometastatic EGC. We investigated outcomes, prognostic factors, and patterns of first progression in these patients. Material/Methods: From 2008-2018, 1438 patients presented to our institution with stage IV EGC. Of these, 189 had oligometastases (defined as ≤5 metastatic lesions, excluding primary) and were included for analysis. 42 patients (22%) had gastric and 147 (78%) had esophageal/GE junction tumors. First progression was classified as limited to initial sites, new sites, or failure at both initial and new sites. OS was stratified by primary tumor site, number of oligometastases, and sites of metastases using Kaplan-Meier and log-rank tests. Cox proportional hazards model was used to investigate correlation between prognostic factors and outcomes. Results: At a median follow up of 22.5 (1-117) months, median OS for the whole cohort was 25 months (95%CI: 22.6-27.4). Most common locations of metastases included non-regional nodes (43%) and liver (16%). The majority of patients presented with either one (43%) or two (25%) sites of oligometastases, and the number or sites of metastases did not correlate with OS. Of 151 patients who progressed, 90 (60%) had isolated initial site failure, 17% had isolated new site failure, and 23% had both. 13% and 12% of patients underwent surgery for primary site and oligometastases, respectively. Radiation therapy (RT) to primary site was delivered to 38%, usually upon progression (58%), while 12% received RT to oligometastases. On univariate analysis, gastric primary, younger age, primary tumor or oligometastases resection, RT to the primary, and isolated initial site failure were significantly associated with better OS. On multivariate analysis, age (HR: 1.03, p=0.006), and initial-site failure (HR: 1.36, p< 0.001) remained significantly correlated with OS. Conclusion: We observed a longer OS for oligometastatic EGC, compared to historical results for general metastatic disease, suggesting these patients are a prognostically distinct group and may benefit from tailored treatment strategies such as ablative local therapy. Most patients first progressed in their initial sites of disease, suggesting a role for local therapy earlier in the treatment course. Younger patients and those undergoing primary tumor resection had superior OS.

Keywords: Oligometastatic disease, esophagogastric cancer