Background: Colorectal carcinoma is the most common malignancy of the gastrointestinal tract. It remains controversial for adjuvant chemotherapy in patients with stage II colon cancer. This study was designed to identify the risk factors of tumor recurrence in stage II colon cancer. Furthermore, the benefit of adjuvant chemotherapy for high-risk stage II colorectal cancer will be investigated.
Materials and methods: From May 1998 until August 2004, 375 patients with stage II (T3N0M0, T4N0M0) colon cancer received curative operation in a single hospital. The clinical data were extracted from the prospectively collected colorectal cancer database. The disease-free survival curves were calculated with Kaplan-Meier's analysis, and the survival difference was determined by log-rank test. The p value less than 0.05 was considered to be significant.
Results: Of 375 stage II colon cancer, 66 patients received 5-FU-based adjuvant chemotherapy, either oral or intravenous (IV) form. Within the median of 48.5 months of follow-up, recurrence developed in 35 patients (9.3%). T4 lesion (p=0.024), lymphovascular invasion (p=0.022), obstruction at presentation (p=0.008), and mucinous component more than 50% (p=0.032) were associated with significantly decreased disease-free survival. High-risk patients (n=102), but not other patients with stage II colon cancer, benefited from adjuvant therapy (3-year disease-free survival: 96.4% vs. 84.7%, p=0.045; 5-year overall survival: 100% vs. 86.4%, p=0.015).
Conclusion: Adjuvant therapy for high-risk stage II colon cancer may be beneficial, and we suggest adjuvant therapy should be considered in high-risk stage II colon cancer patients.