Supplementary Material for: Usefulness of the Preoperative Administration of Tegafur Suppositories as Alternative Adjuvant Chemotherapy for Patients with Resectable Stage II or III Colorectal Cancer: A KODK4 Multicenter Randomized Control Trial

Objective: The aim of this study was to evaluate the feasibility and conferred protection against recurrence of preoperatively administered tegafur suppositories following the intravenous and oral administration of fluoropyrimidine in a multicenter randomized control trial. Methods: Patients with clinical T3/4 colorectal cancer were randomly assigned to receive the preoperative administration of tegafur suppositories (group A) or no preoperative treatment (group B). The primary end points were disease-free survival (DFS) and overall survival (OS). Results: The mean follow-up periods were 80.9 ± 31.0 months in group A and 64.5 ± 28.8 months in group B. The 5-year DFS rates were 89.3% in group A and 70.3% in group B (p = 0.045), whereas the 5-year OS rates were 91.4% in group A and 73.2% in group B (p = 0.051). Furthermore, a significant difference in the cumulative distant metastatic rate was observed (group A, 7.4% vs. group B, 23.4%; p = 0.03). However, no significant difference in the cumulative local recurrence rate was seen (group A, 4.6% vs. group B, 8.2%; p = 0.68). Conclusion: Despite a relatively small sample size, preoperative tegafur suppositories might protect recurrences and improve survival rates, mainly by preventing distant metastasis. These findings suggest the utility of tegafur suppositories as an alternative neoadjuvant treatment in modern chemotherapy for colorectal cancer.