148PEfficacy of capecitabine and oxaliplatin versus S-1 as adjuvant chemotherapy in gastric cancer after D2 lymph node dissection according to lymph node ratio and N stage. (24th November 2019)

• Record Type: Journal Article
• Authors: Lee, S; Kim, I-H; Shin, K
• Is Part Of: Annals of oncology. Volume 30(2019)Supplement 9
• Publication Date: 2019-11-24
• Subjects: Oncology -- Periodicals; 616.992
• DOI: 10.1093/annonc/mdz422.026
• Languages: English
• ISSNs: 0923-7534

Abstract

Abstract: Background: The purpose of this study was to compare Capecitabine and Oxaliplatin (XELOX) with S-1, based on disease-free survival (DFS) and overall survival (OS) in gastric cancer (GC). In addition, clinical impact of using lymph node ratios and compare it with N stage was investigated. Methods: Patients who had curative resection and received either S-1 or XELOX as adjuvant chemotherapy for advanced gastric cancer between Jan, 2011 and Dec, 2015, were analysed. Of the 412 patients enrolled, 301 received S-1 and 111 received XELOX. Lymph node ratio (LNR) groups were segregated as 0, 0-0.1, 0.1-0.25, and > 0.25 and named LNR 0, 1, 2 and 3, respectively. Propensity score matching (PSM) was used to minimize the influence of potential selection bias. The PSM compared DFS and OS in the two treatment groups, and enabled subgroup analysis according to clinical variables including the lymph node ratio group (LNR group) and N stage. Results: In PSM cohort, the sample size of each group was 86 patients and variables are well balanced. The XELOX group showed significantly better DFS (26.9% vs 59.3%, HR 0.43, 95% CI 0.20-0.90; p = 0.025) and better OS(30.8% vs 63.0%, HR 0.44, 95% CI 0.20-0.99; 0.045) in stage IIIC. The XELOX group showed significantly better DFS in all stage III. (54.7% vs 61.6%, HR 0.57, 95% CI 0.33-0.99; p = 0.045). The N3 group showed significantly better DFS (40% vs 65.8%, HR 0.45, 95% CI, 0.23-0.86; p = 0.017) and better OS (44.7% vs 68.4%, HR 0.48, 95% CI, 0.24-0.97; p = 0.040) in the XELOX group. The LNR 3 group showed significantly better DFS in the XELOX group (26.3% vs 52.9% with HR 0.41 (95% CI, 0.17-0.97; p = 0.042). Conclusions: Our data suggested that current N staging and LNR could be a useful tool for selecting patients who can benefit from adjuvant XELOX after D2 gastrectomy when compared with S-1. When patients who are designated N3 or LNR > 0.25 or at stage IIIC, XELOX should be recommended over S-1. Legal entity responsible for the study: The authors. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.