A higher preoperative cachexia index can result in the sufficient administration of S-1 adjuvant chemotherapy and lead to a good prognosis for elderly patients with stage II/III gastric cancer.

Abstract

Purpose: This study aimed to clarify the significance of the relative dose intensity (RDI) of S-1 adjuvant chemotherapy (ACT) after gastrectomy in elderly patients with stage II/III gastric cancer (GC) and to determine whether the cachexia index (CXI) correlates with RDI.

Methods: We enrolled 76 patients with stage II/III GC, aged > 70 years. The overall survival (OS) and disease-specific survival (DSS) of participants in the surgery alone, S-1 ACT completion (RDI ≥ 58%), and S-1 ACT non-completion (RDI < 58%) groups were compared. In addition, the clinicopathological determinants of RDI were examined.

Results: The S-1 ACT completion group had better OS and DSS, while the prognoses of patients in the surgery alone and S-1 ACT non-completion groups did not differ significantly. S-1 ACT non-completion or surgery alone was identified as an independent poor prognostic factor for OS and DSS. Furthermore, a multivariate analysis revealed that a high preoperative CXI (≥ 75.5 for males and ≥ 79.4 for females) was an independent predictor of success in achieving an RDI ≥ 58%.

Conclusions: A higher preoperative CXI can result in a higher RDI and improve the prognosis of elderly patients with stage II/III GC who underwent S-1 ACT.