514 CANCER CELLS PERSIST AFTER COMPLETE PATHOLOGICAL RESPONSE IN ESOPHAGEAL ADENOCARCINOMA

• DOI: 10.1093/dote/doaa087.136
• Publication Date: 2020-09-14T08:44:14Z
• Authors: R Walker; J Harrington; B Grace; B Sharpe; S Breininger; F Izadi; J Kelly; J Byrne; F Noble; M Rose-Zerilli; T Underwood
• Keywords: Esophagectomy; Neoadjuvant Therapy

Abstract In esophageal adenocarcinoma (EAC) with apparent pathological complete response (pCR) to neoadjuvant therapy (NAT) debate remains as whether esophagectomy is required. Recurrence after pCR not limited distant metastases outside radiation or resection fields. It unknown if cancer persists below the lower detection limit of current diagnostic technology. Trials randomising patients active surveillance are currently recruiting in an attempt spare morbidity esophagectomy. Methods Single cell (scRNAseq) was performed on fresh tissue taken at surgical determine transcriptomic profiles populations 24 EAC tumours and matched normal samples. Five tumour-normal pairs were also analysed using bulk RNA sequencing high-precision mass spectrometry proteomics. Immunohistochemistry (IHC) used confirm pCR. Paired scRNAseq analysis pre-and post-treatment specimens from three compare before NAT. Cancer cells assigned a stem module score curated published gene sets. Results We total 22,738 single forming 29 different states. two samples pCR, we repeated IHC antibodies known proteins identified no residual (figure 1A). Bulk 1B) proteomic did detect genes ScRNAseq, conversely, revealed small persistent both responders (12/978 45/774) 1C). Transcriptomic these upregulation markers high scores remaining 1D). Conclusion have determined states present across multiple shown persisting NAT, beneath standard approaches. These express programs consistent cells. critical subpopulation that drive tumour initiation, growth, resistance therapy. Esophagus sparing approaches may subject risk progression.