P1.124. Clinical Outcomes of Esophageal Cancer With Lymph Node Metastasis Invasion Into Other Organs (T4LN)

Abstract

Abstract Topic Esophageal Cancer: Oncology/Radiation Therapy Background The standard treatment for T4 esophageal cancer without distant metastasis is definitive chemoradiotherapy (dCRT). In the Japanese Classification of Esophageal Cancer, 12th Edition, T4 refers to both primary tumor invasion into adjacent organs (T4ESO) and also lymph node metastasis invasion into other organs (T4LN). However, comprehensive data and reports on T4LN are scarce. This study aimed to compare the clinical outcomes of T4ESO and T4LN cases and identify prognostic factors. Methods We evaluated patients diagnosed with T4 thoracic esophageal squamous cell carcinoma who underwent definitive CRT (cisplatin + 5-FU with concurrent radiotherapy, dCRT) at our hospital between May 2007 and August 2021. The patients were categorized into T4ESO and T4LN groups. We retrospectively analyzed overall survival (OS) of each group, and examined the prognostic factors. Results A total of 153 patients (110 in the T4ESO group and 43 in the T4LN group) were included, with a median age of 66 years. The OS rates (T4ESO vs. T4LN) at 1, 2, and 3 years were 74.0% vs. 77.5%, 54.5% vs. 31.8%, and 43.7% vs. 28.9%, respectively. The median survival time was 2.2 years versus 1.2 years (HR 1.81; 95% CI 1.18–2.78). In the multivariate analysis, Performance Status (PS) ≥ 1, T4LN, and Hb < 13.0 g/dL were identified as independent poor prognostic factors. Conclusion Among patients with T4 esophageal cancer treated with dCRT, those with T4LN had a poorer prognosis than those with T4ESO. There is an urgent need to develop more intensive multidisciplinary therapies and novel treatment strategies specifically for T4LN cases.