Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8575, Japan.
Department of Minimally Invasive Surgical and Medical Oncology, Fukushima Medical University, Fukushima, Japan.
Int J Clin Oncol. 2020 Oct;25(10):1807-1813. doi: 10.1007/s10147-020-01719-5. Epub 2020 Jun 12.
A 4-week administration of tegafur/gimeracil/oteracil (S-1) followed by a 2-week rest is the standard adjuvant chemotherapy for surgically resected advanced gastric cancer. This study aimed to evaluate the oncological feasibility of a 2-week S-1 administration followed by a 1-week rest, which is frequently applied in clinical practice to reduce toxicity and improve drug adherence.
We retrospectively enrolled patients with stage II/III gastric cancer who received S-1 adjuvant chemotherapy following radical gastrectomy from 2006 to 2016 in three institutions. Two-week and 4-week regimen cohorts were compared for relative dose intensity (RDI) as a primary outcome, and treatment completion rate, adverse event incidence, overall survival (OS), and relapse-free survival (RFS) as secondary outcomes. Confounders were adjusted for using propensity score matching (PSM).
One hundred and thirty-four patients received the 2-week regimen and 121 patients received the 4-week regimen. Ninety-five patients were extracted from each group after PSM. The RDIs of S-1 in the 2-week and 4-week cohorts were 73.5 and 69.9%, respectively (p = 0.35), which were not significantly different. The treatment completion rate (54.7 vs. 53.7%, p = 1.0), incidence of grade ≥3 adverse events (7.4 vs. 12.6%, p = 0.33), 3-year OS (76.4 vs. 82.7%, p = 0.78), and 3-year RFS (71.3 vs. 73.4%, p = 0.70) did not significantly differ between both cohorts.
The 2-week S-1 adjuvant chemotherapy could not improve drug adherence in terms of RDI, but its relapse rates were not significantly different compared with those of the 4-week regimen. The 2-week regimen might be considered as an option depending on the patient's status.
替加氟/吉美嘧啶/奥替拉西（S-1）四周给药后休息两周是手术切除的晚期胃癌的标准辅助化疗。本研究旨在评估在临床实践中经常应用的两周 S-1 给药后休息一周的方案的肿瘤学可行性，以降低毒性和提高药物依从性。
我们回顾性纳入了 2006 年至 2016 年在三个机构接受根治性胃切除术后 S-1 辅助化疗的 II/III 期胃癌患者。比较两周和四周方案队列的相对剂量强度（RDI）作为主要结局，以及治疗完成率、不良事件发生率、总生存期（OS）和无复发生存期（RFS）作为次要结局。使用倾向评分匹配（PSM）调整混杂因素。
134 例患者接受了两周方案，121 例患者接受了四周方案。PSM 后从每个组中提取了 95 例患者。两周和四周队列的 S-1 的 RDI 分别为 73.5%和 69.9%（p=0.35），无显著差异。治疗完成率（54.7%比 53.7%，p=1.0）、≥3 级不良事件发生率（7.4%比 12.6%，p=0.33）、3 年 OS（76.4%比 82.7%，p=0.78）和 3 年 RFS（71.3%比 73.4%，p=0.70）在两组之间无显著差异。
两周 S-1 辅助化疗在 RDI 方面不能提高药物依从性，但与四周方案相比，其复发率无显著差异。根据患者的情况，两周方案可能是一种选择。
