523. FIVE YEARS OF FLOT THERAPY. RANDOMIZED CONTROLLED TRIAL EVIDENCE IN PRACTICE

Abstract Introduction The combination of 5-flurouracil, oxaliplatin, leucovorin and docetaxel (FLOT) is an effective chemotherapy regime in locally advanced, resectable gastro-oesophageal adenocarcinoma. Since the FLOT4-AIO randomised controlled trial demonstrated superiority over ECF/ECX it has been standard of care at many centres and European Society of Medical Oncology’s recommended perioperative regimen. After over five years of offering this treatment to patients we assessed how this evidence had translated into practice; identifying factors that predict dose reduction or incomplete therapy and overall survival. Method Patients who had the combination of neoadjuvant FLOT chemotherapy and oesophagectomy for adenocarcinoma of the oesophagus or gastro-oesophageal junction between February 2018 and September 2023 were identified from a prospectively collected database. Data on completion of chemotherapy, perioperative outcomes and long-term survival were collected. Pathological regression was assessed using Mandard tumour regression grade (TRG). The peri-operative, pathological, and long-term outcomes of patients who completed four cycles of neoadjuvant FLOT was compared with those who had reduced dose or early cessation. Statistical analysis used IBM SPSS, with Mann-Whitney U and Chi squared for variable analysis and univariate cox regression for survival. Results Eighty patients were included with a median age of 66 (47-79), 84% were male. Full dose completion was achieved by 57 (71%) patients, 20 (25%) had dose reduction and 7(8%) did not complete four cycles. Age, anaerobic threshold and VO2 max were not significantly different between those completing or not completing neoadjuvant chemotherapy (p=0.460, p=0.624, p=0.104 respectively); or requiring dose reductions (p=0.317, p=0.587, p=0.82). Median TRG across all three groups was 3. Median follow up was 55.4 months and mean overall survival was 53.4 months. No difference in survival was observed between those who completed or did not complete neoadjuvant FLOT (p=0.45). Conclusion Completion of neoadjuvant chemotherapy was lower in this cohort of patients than FLOT4-AIO. Rates of pathological complete response were similar. This translated into similar mean overall survival. Median survival was unable to be calculated as survival exceeds 50% at the time of our study. The use of FLOT has translated well into the routine neoadjuvant clinical setting with acceptable short- and long-term outcomes.