High-risk clinicopathological features and their predictive significance in Korean patients with stage II colon cancer

Purpose: We investigated the prognostic factors for recurrence in Korean patients with stage II colon cancer and evaluated their predictive significance with 5-fluorouracil (FU)-based adjuvant chemotherapy. Methods: We analyzed the relationship between clinicopathological features and relapse-free survival (RFS) of 716 stage II colon cancer patients who underwent curative resection. Predictive values were assessed using 5-year RFS and 5-year cancer-specific survival (CSS). Results: The 5-year RFS, 5-year CSS, 5-year disease-free survival, and 5-year overall survival rates were 87.4, 94.9, 84.8, and 90.5 %, respectively. T4 stage (hazard ratio [HR], 2.342; 95 % confidence interval [CI], 1.348–4.068; p = 0.003), preoperative bowel obstruction or perforation (HR 2.428; 95 % CI 1.241–4.752; p = 0.010), and age older than 70 years (HR 1.740; 95 % CI 1.130–2.678; p = 0.012) were poor prognostic factors for recurrence in multiple Cox regression analyses. In 60 patients with T4 disease, 5-FU-based adjuvant chemotherapy was associated with improved 5-year CSS of the patients (90.3 vs. 46.7 %; HR 0.135; 95 % CI 0.035–0.517; p = 0.003). Conclusions: We found discordance between the risk factors for recurrence and the predictive value for 5-FU-based adjuvant chemotherapy in Korean patients with stage II colon cancer. Future prospective clinical trials selectively targeting high-risk patients are needed.