P1.130. Influence of Recurrence Timing and Site on Outcomes of Oligo-Recurrence After Curative Esophagectomy

Abstract

Abstract Topic Esophageal Cancer: Oncology/Radiation Therapy Background Esophageal cancer remains associated with high mortality and frequent recurrence despite advances in perioperative treatment. The concept of oligometastasis has gained attention, as selected patients may achieve prolonged survival with multidisciplinary treatment. However, the optimal strategy for oligo-recurrence after curative esophagectomy remains unclear. Methods Among 497 patients who underwent R0 esophagectomy between 2010 and 2020, 161 who developed recurrence were analyzed. Oligo-recurrence was defined as recurrence in a single organ with ≤5 lesions or lymph node recurrence confined to a single region with ≤5 nodes. Early recurrence was defined as recurrence within 6 months after surgery. Patients were categorized into four groups according to oligo-recurrence and timing of recurrence, and overall survival (OS) and survival after recurrence were compared. In addition, outcomes were analyzed according to recurrent organ in the oligo-recurrence cohort. Multivariate analysis was performed to identify prognostic factors. Results Of the 161 recurrent cases, 33 (20%) had non-early oligo-recurrence, 20 (12%) had early oligo-recurrence, 43 (27%) had non-early non-oligo-recurrence, and 65 (40%) had early non-oligo-recurrence. Patients with non-early oligo-recurrence demonstrated the most favorable OS (p<0.0001), whereas early oligo-recurrence showed survival comparable to non-early non-oligo-recurrence.Within the oligo-recurrence cohort, recurrence sites included lymph nodes (n=34), liver (n=7), lung (n=5), and others (n=7). Median survival after recurrence was 49 months for lymph node recurrence and 14 months for liver recurrence (p=0.011). Curative treatment (surgery or chemoradiotherapy) was an independent favorable prognostic factor (HR 0.203, p=0.006). Conclusion In patients with oligo-recurrence after curative esophagectomy, prognosis varies according to both timing and site of recurrence. Curative treatment may improve survival, particularly in lymph node recurrence without early recurrence. Treatment strategies should therefore incorporate both time to recurrence and site of recurrence.