Fluorescence Molecular Endoscopy (FME) Using Bevacizumab-800CW to Evaluate Response to Neoadjuvant Chemoradiotherapy in Esophageal Cancer: Preliminary Results

Aims Currently, patients diagnosed with locally advanced esophageal adenocarcinoma receive neoadjuvant chemoradiotherapy (nCRT) followed by esophagectomy independent of the patients’ response to nCRT. Roughly 16-43 % of esophageal cancer patients will achieve a pathological complete response (pCR) after nCRT1. Current imaging devices cannot adequately distinguish pCR from pathological partial response (pPR) before esophagectomy2. There is a need for a reliable pre-operative method which can precisely distinguish pCR from pPR and prevent (possibly) unnecessary surgery.

MethodsThis study aims to determine the safety and feasibility of fluorescence molecular endoscopy (FME) using bevacizumab-800CW for identification of pCR after nCRT in patients with esophageal adenocarcinoma. Patients were intravenously injected with either 4.5, 10 or 25 mg bevacizumab-800CW 3 days prior to the endoscopy. FME was performed to monitor the effect of the nCRT and biopsies were taken from normal and (residual) tumor area. Multi-diameter single fiber spectroscopy/single fiber fluorescence (MDSFR/SFF) spectroscopy was used to quantify the intrinsic fluorescence intensity, both in-vivo and ex vivo.

Results In this ongoing trial, patients diagnosed with locally advanced esophageal adenocarcinoma scheduled for neoadjuvant chemoradiotherapy followed by surgery were enrolled between November 2018 and November 2020. No tracer related (serious) adverse events were observed. The preliminary results show a significant difference between normal esophageal tissue and residual area in all three dose groups based on quantitative MDSFR/SFF spectroscopy measurements. When considering the signal-to-background ratio (SBR), it shows a value of 1.36±0.08, 1.83±0.46 and 1.97±0.97 for 4.5, 10 and 25 mg respectively. This could be the results of the variation in TNM stage and Mandard score within these dose groups.

Conclusions Preliminary results show that Bevacizumab-800CW is safe for administration in patients with locally advanced esophageal adenocarcinoma. The current dose escalation study will be extended to find the optimal dose for treatment monitoring.

Citation: Schmidt I, Zhao X, Kats-Ugurlu G et al. OP76 FLUORESCENCE MOLECULAR ENDOSCOPY (FME) USING BEVACIZUMAB-800CW TO EVALUATE RESPONSE TO NEOADJUVANT CHEMORADIOTHERAPY IN ESOPHAGEAL CANCER: PRELIMINARY RESULTS. Endoscopy 2021; 53: S32.

Publication History

Article published online:
19 March 2021