P-OGC65 Patterns and timing of recurrence following resection of oesophago-gastric adenocarcinoma. (16th December 2021) - Shen, William
Abstract: Background: Recurrence following resection of oesophago-gastric adenocarcinoma (OGA) is frequent and associated with poor outcomes. Predictors of site, timing and mechanisms driving recurrence is poorly defined, which limits the development of anti-metastatic agents. The aim of this study was to investigate the patterns and timing of recurrence following resection of OGA. Methods: Retrospective review of a prospectively maintained resection database from the Glasgow Royal Infirmary oesophago-gastric unit of patients undergoing surgery for OGA. Primary outcomes were recurrence and cancer specific death following surgery. Recurrence patterns were defined as liver, lung, peritoneal, locoregional only and other distant groups. The latter is a heterogenous group that do not include any liver, lung, or peritoneal metastases. Results: N = 635 patients were identified having undergone surgical resection of OGA. Of these, n = 262 developed confirmed recurrent disease. Liver metastases (n = 86, 33%) were the most common site of recurrence, followed by peritoneal (n = 35, 13%), lung (n = 33, 13%) locoregional only (n = 51, 20%) and other distant sites (n = 57, 22%). Liver recurrence was associated with significantly worse disease specific (19.1 vs 28.2 months, P < 0.001) and recurrence free survival (P = 0.006). There was no association between site of recurrence and known prognostic clinicopathological factors, including anaerobic threshold (P = 0.810), nodal status (P = 0.088), pathological T-stage (P = 0.357), differentiation (P = 0.195), deprivation index (P = 0.996), perineural (P = 0.475) or lymphovascular (P = 0.422) invasion. Conclusions: Liver metastases is the most common site of recurrence following surgery for OGA. Prognostic clinical and pathological factors do not determine the site of recurrence, suggesting that molecular features of the primary tumour determine and promotes recurrence patterns. Further study to delineate the molecular and microenvironment factors driving recurrence patterns is urgently required.