Univariate Cox regression analysis of 4-year progression-free survival and overall survival in relation to patients’ characteristics.

a. only oral regimens: XELODA and UFUR groups;b. combined regimens: FOLFOX, XELOX, OXA then 5-FU and FL groups.Abbreviations: 4-y OS: 4-year overall survival; 4-y PFS: 4-year progression-free survival; 95% CI: 95% confidence interval; CEA: carcinoembryonic antigen; ECOG: Eastern Cooperative Oncology Group performance status; FL: 5-Fluorouracil (5-FU)/leucovorin; FOLFOX: mFOLFOX 6, 5-FU/leucovorin/oxaliplatin; LNR: the positive lymph node ratio of dissected lymph nodes; OXA: oxaliplatin; OXA then 5-FU: Oxaliplatin-based chemotherapy (less than 8 cycles of 5-FU/leucovorin/oxaliplatin or less than 6 cycles of oral capecitabine/intravenous oxaliplatin) followed by 5-FU-based chemotherapy (5-FU/leucovorin, oral tegafur-uracil/folinate calcium or oral capecitabine); P: probability value; RR: relative risk; TNM stage: Cancer staging system which was developed and is maintained by the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC) is based on the extent of the tumor (T), the extent of spread to the lymph nodes (N), and the presence of metastasis (M); UFUR: oral UFUR/LV, tegafur-uracil/oral folinate calcium (leucovorin); vs: versus; XELODA: oral capecitabine; XELOX: CapeOx, oral capecitabine/intravenous oxaliplatin; y/o: years old.