Exclusive neoadjuvant chemotherapy with the FLOT regimen protocol in resectable gastric cancer: A retrospective cohort study in a Brazilian reference center.

Abstract

e16118 Background: Perioperative chemotherapy with fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT) is currently considered the standard of care for patients with resectable gastric and esophagogastric junction adenocarcinoma. However, completion of postoperative chemotherapy remains a major challenge, particularly in real-world and public healthcare settings. In this context, some centers have adopted an exclusive neoadjuvant approach, delivering all eight cycles before surgery. This study aimed to evaluate the feasibility, safety, and oncologic outcomes of this exclusive neoadjuvant strategy. Methods: We retrospectively analyzed 32 consecutive patients with resectable gastric or esophagogastric junction adenocarcinoma (≥cT2 and/or cN+) treated between 2019 and 2024 with neoadjuvant FLOT followed by surgery at a Brazilian reference center. Patients were grouped according to the number of neoadjuvant cycles received (≤4 vs > 4). Clinical, pathological, and survival outcomes were assessed. Overall survival (OS) was calculated from diagnosis and disease-free survival (DFS) from curative-intent surgery. Survival analyses were performed using Kaplan-Meier estimates and the log-rank test. Results: Twenty-one patients (65.6%) completed all eight neoadjuvant cycles, and 84.3% received more than four cycles. Dose reductions were required in 50% of cases. Curative-intent surgery was performed in 87.5%, with a mean of 25 lymph nodes retrieved. The R0 resection rate was 75%. Pathological complete response occurred in 9.4%, and pathological downstaging in 25%. Postoperative complications occurred in 18.8%, with no perioperative mortality. Mean OS estimate was 45.3 months in patients receiving more than four cycles versus 18.7 months in those receiving four or fewer cycles (p = 0.0096). Mean DFS estimate was 41.1 versus 18.6 months, respectively (p = 0.028). Toxicity was manageable, although 50% required dose adjustments. Conclusions: Delivering all eight cycles of FLOT exclusively in the neoadjuvant setting was feasible and safe in this Brazilian real-world cohort, with high adherence and encouraging survival outcomes. This strategy may represent a pragmatic alternative in scenarios of low compliance with adjuvant treatment or limited access to postoperative chemotherapy, warranting prospective validation. Treatment delivery, surgical feasibility, and oncologic outcomes. Variable Result Patients, n 32 Completed all 8 neoadjuvant cycles 21 (65.6%) Received >4 neoadjuvant cycles 27 (84.3%) Dose reduction required 16 (50%) Mean lymph nodes retrieved 24.9 ± 12.0 Pathological complete response (ypT0N0) 3 (9.4%) Pathological downstaging 8 (25%) Mean OS, months (>4 vs ≤4 cycles) 45.29 vs 18.71 Mean OS, months (dose reduction yes vs no) 30.83 vs 54.43