Genomic correlates with survival after treatment of oesophageal adenocarcinoma by surgery alone

New prognostic biomarkers for oesophageal adenocarcinoma (OAC) may help treatment planning as current staging does not accurately predict survival for many patients. We used a 451 cancer-associated gene panel to assess genomic alterations associated with survival for a cohort of 65 OAC patients who underwent surgical resection without perioperative treatment, reflecting institutional practice at the time. Median age at operation was 72 years, 88% were male, median 32 lymph nodes were removed per patient, and minimum follow-up exceeded 11 years. TNM stages (pTNM, 8th ed.) were 14% stage 1, 14% stage 2, 45% stage 3, and 6% stage 4 (non-locoregional nodal metastases). Copy number changes were common, and somatic mutations were similar to those reported previously. Genetic associations with worse survival included amplification of CCND1 (HR=3.08, p=0.02), EGFR (HR=2.98, p=0.01), loss of ARID2 (HR=2.12, p=0.05), KMT2D (HR=1.99, p=0.07) and missense mutation within RYR1 (HR=2.68, p=0.01). This study identifies candidate genomic prognostic biomarkers in OAC using a cohort treated by surgery alone, enabling assessment of tumour biology independent of the confounding effects of peri-operative systemic therapy and radiotherapy. Several of the identified alterations are potentially targetable, supporting further investigation of genomic profiling to refine prognostication and guide treatment selection.