Adjuvant chemotherapy with tegafur/uracil for more than 1 year improves disease-free survival for low-risk Stage II colon cancer.

Background: It is uncertain whether adjuvant chemotherapy (CMT) improves survival in patients with low-risk Stage II colon cancer. We aimed to determine the disease-free survival (DFS) and 5-year overall survival (OS) of low-risk Stage II colon cancer patients treated with adjuvant tegafur/uracil (UFUR).

Methods: From January 2004 to December 2011, the follow-up status of 278 low-risk Stage II colon cancer patients who underwent surgery in a single medical center was retrospectively analyzed. These patients were divided into three groups based on whether they received adjuvant CMT with UFUR, adjuvant CMT with 5-fluorouracil, or surgery alone. DFS and 5-year OS curves were calculated using Kaplan-Meier survival analysis and Cox proportional hazards regression.

Results: In the study population, including 278 low-risk Stage II colon cancer patients with a mean age of 68.28 ± 13.01 years, 132 (47.5%) received adjuvant CMT with UFUR, 49 (17.6%) received adjuvant CMT with 5-fluorouracil, and 97 (34.9%) underwent radical surgery alone. At 5 years, the adjusted DFS and OS of low-risk Stage II colon cancer patients were 85.5% and 81.8%, respectively, in the surgery alone group and 97.9% and 96.2%, respectively, in the surgery plus UFUR > 12 months group (p = 0.004 and p = 0.098, respectively). In multivariate analysis, CMT with UFUR for more than 12 months increased DFS over surgery alone. There was no statistical difference in the 5-year OS.

Conclusion: Adjuvant CMT treatment of low-risk Stage II colon cancer patients with UFUR for more than 12 months following surgery improves DFS over surgery alone.