526. COMPARISON OF CANCER CACHEXIA DEFINITIONS AND THEIR ASSOCIATION WITH OVERALL SURVIVAL IN PATIENTS WITH INCURABLE OESOPHAGOGASTRIC CANCER

Abstract Background Cancer cachexia is highly prevalent in oesophagogastric cancer, particularly amongst patients with advanced stage disease. However, classifications for cachexia remain heterogenous within the existing literature. The aim of this study is to compare prognostication using the Fearon et al. consensus definition to the Global Leadership Initiative on Malnutrition (GLIM) criteria, in patients with incurable oesophagogastric cancer. Methods Consecutive patients with newly diagnosed incurable oesophagogastric cancer between 2019-2020 were identified from a prospectively maintained regional database. Data were collected regarding demographics, clinicopathological details, patient-reported involuntary weight loss and body mass index. CT body composition analysis was performed using staging scans and neutrophil-lymphocyte-ratio was retrieved as a marker of inflammation at the time of diagnosis. These data allowed comparison based on Fearon and GLIM classifications for cachexia. The primary outcome of interest was overall survival. Results Overall, 330 patients (66.9% male, median 74 years) were diagnosed with incurable oesophageal (70.6%) or gastric cancer (29.4%) during the study period. Of these 65.5% (n=216) met the Fearon definition of cachexia at diagnosis, while 64.8% (n=214) could be diagnosed based on the GLIM criteria. Both diagnostic criteria were met by 148 patients (47.9%). Clinicopathological characteristics were all broadly comparable between cachectic and non-cachectic groups based on both classifications. Worse overall survival was seen in cachectic patients using Fearon (median: 118 vs. 228 days) and GLIM (median: 114 vs. 245 days) diagnostic criteria (both p<0.001). Following adjustment for known confounders, cachexia diagnosed based on the GLIM criteria (HR 1.60 (95%CI: 1.25-2.05), p<0.001) was more strongly associated with adverse survival than that diagnosed using the Fearon criteria (HR: 1.44 (95%CI: 1.13-1.84), p=0.003)). Conclusion Cancer cachexia is strongly associated with worse survival in patients with incurable oesophagogastric cancer. Diagnosis based on the GLIM criteria appears to have the greatest prognostic effect.