P1.103. Evaluation of the Efficacy of Local Therapy for Postoperative Oligo-Recurrence in Esophageal Squamous Cell Carcinoma

Abstract

Abstract Topic Esophageal Cancer: Management of Metastatic Cancer Background Postoperative recurrence of esophageal squamous cell carcinoma (ESCC) is associated with poor prognosis. Among recurrent patterns, oligo-recurrence (OR) has attracted attention because long-term survival may be achieved by combining systemic therapy with local treatments. However, the optimal treatment strategy for OR remains controversial. Methods We retrospectively analyzed patients with postoperative OR of ESCC who underwent curative esophagectomy between January 2011 and March 2025 at our institution. OR was defined as up to three recurrent lesions within a single organ or up to three lymph node metastases within the same field. Overall survival (OS) and progression-free survival (PFS) were compared between patients who received local therapy (surgical resection or radiotherapy) and those treated with systemic therapy alone. Patients who achieved clinical complete response after treatment for recurrent lesions and subsequently developed OR were also included. OS and PFS were defined as the time from initiation of treatment for recurrent lesions to death, and to death, recurrence, or disease progression, respectively. Disease-free interval (DFI) before recurrence was defined as the time from achievement of clinical complete response to diagnosis of recurrence. Multivariable Cox proportional hazards regression analysis was performed to identify independent prognostic factors for OS. Results A total of 110 patients with postoperative OR were included. Treatment strategies consisted of systemic therapy alone (n=27), resection alone (n=23), resection plus systemic therapy (n=6), resection plus radiotherapy (n=8), radiotherapy including FP-based chemoradiotherapy (n=33), and radiotherapy plus systemic therapy (n=13). Accordingly, 83 patients received local therapy and 27 received systemic therapy alone. Median DFI before recurrence was significantly longer in the local therapy group than in the systemic therapy alone group (336 vs. 185 days, p=0.03). Five-year OS and PFS rates were significantly higher in the local therapy group than in the systemic therapy alone group (38% vs. 0%, p<0.01; 32.9% vs. 0%, p=0.01, respectively). On multivariable analysis, local therapy was an independent favorable prognostic factor for OS (HR 0.50; 95% CI 0.28–0.88; p=0.02). Conclusion Local treatments such as surgical resection and radiotherapy, when incorporated into multidisciplinary management for postoperative oligorecurrence of ESCC, may contribute to prolonged overall survival. Given recent advances in systemic therapies, including immune checkpoint inhibitors, further studies are warranted to establish optimal multidisciplinary treatment strategies that integrate local and systemic approaches for patients with postoperative oligorecurrence.