Retrospective comparison of capecitabine plus oxaliplatin and docetaxel plus S-1 as adjuvant chemotherapy for pathological stage III gastric cancer

BACKGROUND: Adjuvant chemotherapy following surgical resection is the standard treatment for patients with pathological stage III (pStageIII) gastric cancer (GC) in Japan. Capecitabine plus oxaliplatin (CapeOX) and docetaxel plus S-1 (DS) are recommended adjuvant regimens for this disease; however, no studies have compared the treatment outcomes of the two regimens. Therefore, this study aimed to evaluate the safety and efficacy of CapeOX versus DS as adjuvant chemotherapy in patients with pStage III GC. METHODS: We retrospectively reviewed the clinical information and treatment outcomes (including relapse-free survival [RFS] and adverse events) of patients with pStageIII GC who received either CapeOX or DS as adjuvant chemotherapy at our institution from February 2016 to May 2022 Results: A total of 73 patients (CapeOX, 31; DS 42) were included in this study. There was no significant difference in RFS between the two groups (3-year RFS: 37% in the CapeOX group vs. 44% in the DS group; HR=1.30 [95% CI: 0.71-2.37], p=0.400). In the multivariable analysis for RFS, treatment regimen was not identified as a prognostic factor for RFS (HR=1.02, [95% CI: 0.49-2.09], p=0.957). Compared with DS, CapeOX was associated with lower incidences of any-grade oral mucositis (10% vs. 50%, p<0.001) and any grade alopecia (6% vs. 74%, p<0.001), and a higher incidence of any-grade peripheral sensory neuropathy (81% vs. 24%, p<0.001). CONCLUSIONS: This analysis suggests that CapeOX and DS offer comparable efficacy as adjuvant chemotherapy for pStageIII GC in terms of RFS, while exhibiting distinct adverse event profiles.