295. SAFETY OF SURVEILLANCE GASTROSCOPY AND ENDOSCOPIC ULTRASONOGRAPHY IN THE OESOPHAGUS AFTER NEOADJUVANT CHEMORADIOTHERAPY: RESULTS FROM THE SANO COHORT

Abstract Background An organ sparing strategy has been proposed for patients with oesophageal cancer and a clinically complete response after neoadjuvant chemoradiotherapy (nCRT). This active surveillance strategy involves (repeated) oesophagogastroduodenoscopy (OGD) with bite-on-bite biopsies and endoscopic ultrasonography (EUS). The preSANO trial and preliminary results of the SANO trial concluded that these procedures are safe to identify those with a clinically complete response. However, the safety of these procedures beyond that timeframe remains unknown. The aim of this study is to assess the safety of endoscopic procedures after nCRT, extending beyond three months. Methods This is a retrospective multicentre cohort study. All patients who participated in the pre-SANO and SANO studies were included. All were treated with CROSS nCRT for oesophageal cancer and underwent (repeated) endoscopic response evaluations (OGD with bite-on-bite biopsies and/or EUS with fine needle aspiration, as indicated). Primary outcome was serious adverse events (SAE) as defined by Central Committee on Research Involving Human Subjects (CCMO) associated with endoscopic procedures which include (but are not limited to) bleeding, infection and perforation. Secondary outcome included mechanical injury. Results A total of 919 patients underwent at least one endoscopic response evaluation. Some 2355 endoscopic procedures (61% OGD with EUS combined, 33% OGD and 6% EUS) were performed. Of these, 819 (35%) were performed more than three months after nCRT. SAEs were reported for five endoscopic procedures (0.2%) and included three cases of gastrointestinal bleeding after OGD with biopsies and two cases with infection secondary to the endoscopic procedures. No significant difference in SAEs was found between the procedures conducted before and more than three months after nCRT (2 vs. 3, OR 2.8, 95% CI, 0.3 – 33.7, P = 0.35). Conclusion OGD with biopsies and EUS are both procedures which can be safely performed after nCRT during an active surveillance strategy.