480. OUTCOMES OF ADJUVANT LOCAL TREATMENT AFTER ESOPHAGEAL SURGERY WITH POSITIVE RESECTION MARGIN IN INTRATHORACIC ANASTOMOSIS

Abstract

Abstract Esophageal cancer is aggressive diseases requiring surgery as an essential part of treatment. To achieve increased overall survival, complete resection (R0) is preferred. In some case, however, we encounter positive resection margin (R1). Further resection will be required, but sometimes it is difficult to do additional procedure because of various reasons, especially the highest location of anastomosis. Hypothesis of study is that R1 resection with adjuvant local therapy shows comparable result with R0 resection in intrathoracic anastomosis From 2000 to 2017, total 2723 patients received the esophagectomy and mediastinal lymph node dissection for esophageal cancer. R0 resection was 1701, and R1 resection was 76 patients. Patients who received distal esophagectomy (n=56) and lack of information about adjuvant therapy (n=24) were excluded Because of differences in some variables, we conducted 2:1 propensity score matching to reduce differences between groups. Comparison of R1 resection group with adjuvant local therapy to R0 resection group is conducted Overall survival (OS) and recurrence free survival (RFS) were estimated with Kaplan-Meier method. 76 patients were identified with R1 resection. Of those patients, 30 patients showed positive proximal resection margin from frozen section during surgery. When compared to R0 resection group (including patients with adjuvant treatment), OS and RFS were statistically lower in R1 resection group (p=0.03 and 0.023, respectively) When comparing R1 with adjuvant local treatment group to R0 resection group, there were no statistical differences in both OS and RFS.(p=0.13 and 0.22, respectively) In R1 resection group, adjuvant local treatment group show favorable result compared to non-local treatment group, but there were no statistical differences in OS and RFS.(p=0.26 and 0.17, respectively) R1 resection with proper adjuvant local treatment enable us to achieve comparable result with R0 resection group in intrathoracic anastomosis When anastomosis is made at the highest level of thorax (i.e. thoracic inlet level), it is not easy to perform additional intrathoracic resection. If it is difficult to do further resection when resection margin is positive, adjuvant local treatment after surgery can be one reasonable option to improve patient’s survival or minimize disease recurrence