Significance of Neoadjuvant S-1-Based Chemotherapy for Older Patients With Locally Advanced Gastric Cancer.

Background: Neoadjuvant chemotherapy (NAC) has been extensively developed for locally advanced gastric cancer (GC). In Asia, S-1-based regimens, such as docetaxel, oxaliplatin, and S-1 (DOS) and S-1 and oxaliplatin (SOX), are expected to become the standard of care. However, the data on the significance of NAC for older patients with advanced GC remains scarce. Therefore, this study aimed to evaluate the feasibility and efficacy of NAC in older patients. Methods: We retrospectively analyzed the data from patients with cStage II-III locally advanced GC who underwent radical surgery at our institution between 2015 and 2021. This study included three groups: 56 patients with NAC and age < 75 years (NAC-Young group), 20 with NAC and age ≥ 75 years (NAC-Older group), and 46 without NAC and age ≥ 75 years (OP-Older group). Patient backgrounds, adverse events of NAC, and prognoses were compared among the groups. Results: Compared with the NAC-Young group, the NAC-Older group was more likely to receive the SOX regimen and reduced initial doses, but there was no significant difference in the incidence of adverse events of NAC and prognosis. Compared to the OP-Older group, overall survival and cancer-specific survival tended to be better in the NAC-Older group at cStage III. Moreover, for patients with cStage III and ECOG-PS 0, cancer-specific survival was significantly better in the NAC-Older group compared to the OP-Older group ( Conclusions: NAC with S-1-based regimens is a feasible and effective treatment option for older patients with GC with advanced-stage disease and good overall condition.