Clinical management of perioperative FLOT for resectable gastric, gastroesophageal junction, or esophageal adenocarcinoma: Practical insights from a Japanese single-institute experience.

341 Background: Perioperative FLOT (fluorouracil, leucovorin, oxaliplatin, and docetaxel) has been the standard of care for patients with resectable locally advanced gastric and gastroesophageal junction cancer (GC/GEJC). However, real-world management data remain limited. Methods: We retrospectively reviewed patients with adenocarcinoma of gastric, GEJ and esophageal who received perioperative FLOT until January 2025. Results: A total of 149 patients (median age 70; 29% ≥75 years), 130 patients (87%) completed four cycles of preoperative FLOT, and 137 (92%) underwent surgery. Postoperative FLOT was initiated in 101 patients (68%) and completed in 83 patients (56%). Prophylactic peg G-CSF, administered in 60.4% of cases, significantly reduced the incidence of grade ≥3 neutropenia (7% vs 81%, p < 0.001) and febrile neutropenia (2% vs 10%, p = 0.043). Thirty-seven patients, including 29 patients aged ≥75 years, initiated FLOT at a reduced dose. Older patients more frequently required outpatient IV fluid during preoperative FLOT (56% vs. 33%, p = 0.010), although R0 resection rates were comparable (86% vs. 92%). Postoperative FLOT initiation (51% vs 75%, p = 0.006) and completion (40% vs 62%, p = 0.011) were lower in older patients. IV fluid support was needed in 32% during cycle 1 but decreased with subsequent cycles. Emergency hospitalization due to anorexia occurred in 7%; none had received prophylactic olanzapine. Hospitalization was more frequent after total gastrectomy (15%) compared to other surgical procedures. Conclusions: Appropriate dose modification and interim visits with IV fluid administration for high-risk patients may be useful in the clinical management of perioperative FLOT. Prophylactic use of G-CSF and multiple antiemetic agents may improve the feasibility in daily clinical practice.