Delayed Initiation of Postoperative S-1 Adjuvant Chemotherapy Worsens Prognosis After Gastric Cancer Recurrence

Background/Aim: Previous reports revealed the negative prognostic factors for patients with gastric cancer (GC) who received curative surgery plus postoperative S-1 chemotherapy. However, there were few reports on the survival time of patients after the recurrence of GC. Therefore, this study aimed to investigate overall survival (OS) after the recurrence of GC in patients who received postoperative S-1 chemotherapy. Patients and Methods: We retrospectively analyzed 44 consecutive patients with Stage II-III GC who received postoperative S-1 chemotherapy between 2013 and 2017 but relapsed. Results: The S-1 initiation time (<50 days) was the significant prognostic factor (p=0.002). Multivariate analysis using the Cox proportional hazard model revealed that the S-1 initiation time (≤50 days) was independent poor prognostic factor for OS after recurrence (p=0.017). Logistic regression analysis revealed that postoperative prognostic nutritional index (PNI) (<38.9) (p=0.002) and postoperative complications (p=0.014) were independent risk factors for the proper initiation time. Conclusion: OS after recurrence was extended by initiating the postoperative chemotherapy within 50 days. Postoperative nutritional management and reduction of postoperative complications may prevent a delay in the initiation of postoperative S-1 chemotherapy and improve the prognosis.