Safety and efficacy of perioperative FLOT regimen in Japanese patients with gastric, esophagogastric junction, or esophageal adenocarcinoma: a single-institution experience

•Safety and efficacy of FLOT in Japanese gastric/junction/esophageal adenocarcinoma.•Primary prophylactic G-CSF effectively prevent neutropenia and febrile neutropenia.•Limited efficacy of FLOT in dMMR/MSI-H cases. BackgroundAlthough the common treatment strategy for localized gastric cancer in Japan is gastrectomy followed by adjuvant chemotherapy, several randomized studies in non-Japanese populations have established perioperative chemotherapy as the standard treatment of localized gastric or gastroesophageal junction adenocarcinoma. Therefore, we have implemented this strategy in our institution.Patients and methodsWe retrospectively reviewed the medical records of patients with resectable gastric cancer, gastroesophageal junction cancer, and esophageal adenocarcinoma who had received perioperative FLOT (5-fluorouracil plus docetaxel plus oxaliplatin plus leucovorin) from February 2020 to February 2023.ResultsIn this study, a total of 91 patients were analyzed, with a median age of 70 years (range: 29-82). At the time of diagnosis, 83 patients (91.2%) had T3 or higher-grade primary lesions, and 85 (93.4%) had lymph node metastasis. A total of 10 patients had resection before completing four cycles of preoperative chemotherapy, and 77 of 91 (84.6%) completed four cycles with 74 of them receiving radical resection. Among the 84 patients who had radical resection after FLOT, 82 (97.6%) achieved R0 resection, including 8 (9.5%) with a pathological complete response. After resection, 60 patients (65.9%) received at least one cycle of post-operative FLOT, and 47 (51.6%) completed eight cycles of FLOT treatment. Chemotherapy-related adverse events of grade 3 or higher occurred during the pre- and post-operative FLOT in 60 patients (65.9%), including leukopenia (30.8%), neutropenia (50.5%), febrile neutropenia (5.5%), and anorexia (7.7%). No treatment-related deaths occurred.ConclusionsThese findings were comparable to those in the pivotal FLOT 4 trial, suggesting acceptable feasibility of the FLOT regimen in Japanese clinical practice. Although the common treatment strategy for localized gastric cancer in Japan is gastrectomy followed by adjuvant chemotherapy, several randomized studies in non-Japanese populations have established perioperative chemotherapy as the standard treatment of localized gastric or gastroesophageal junction adenocarcinoma. Therefore, we have implemented this strategy in our institution. We retrospectively reviewed the medical records of patients with resectable gastric cancer, gastroesophageal junction cancer, and esophageal adenocarcinoma who had received perioperative FLOT (5-fluorouracil plus docetaxel plus oxaliplatin plus leucovorin) from February 2020 to February 2023. In this study, a total of 91 patients were analyzed, with a median age of 70 years (range: 29-82). At the time of diagnosis, 83 patients (91.2%) had T3 or higher-grade primary lesions, and 85 (93.4%) had lymph node metastasis. A total of 10 patients had resection before completing four cycles of preoperative chemotherapy, and 77 of 91 (84.6%) completed four cycles with 74 of them receiving radical resection. Among the 84 patients who had radical resection after FLOT, 82 (97.6%) achieved R0 resection, including 8 (9.5%) with a pathological complete response. After resection, 60 patients (65.9%) received at least one cycle of post-operative FLOT, and 47 (51.6%) completed eight cycles of FLOT treatment. Chemotherapy-related adverse events of grade 3 or higher occurred during the pre- and post-operative FLOT in 60 patients (65.9%), including leukopenia (30.8%), neutropenia (50.5%), febrile neutropenia (5.5%), and anorexia (7.7%). No treatment-related deaths occurred. These findings were comparable to those in the pivotal FLOT 4 trial, suggesting acceptable feasibility of the FLOT regimen in Japanese clinical practice.