Oral fluoropyrimidines may not reduce the risk of postoperative recurrence in colorectal cancer associated with mesenteric lymph node metastasis.

To clarify the efficacy and problems of postoperative adjuvant chemotherapy using oral fluoropyrimidines, the clinicopathological data of 307 colorectal cancer patients treated with or without postoperative chemotherapy were analyzed retrospectively. Patients in the chemotherapy group (n = 188) who underwent curative resection were followed by administration of oral fluoropyrimidine. The other 119 patients underwent surgery alone. The disease-free survival rates were compared between the two groups. The disease-free survival rate in the chemotherapy group was significantly higher than that in the surgery alone. However, no significant difference in disease-free survival rate was found for those with tumors that were associated with mesenteric lymph node involvement and tumors with a high grade of lymphatic invasion or high grade of venous invasion. Postoperative adjuvant chemotherapy using oral fluoropyrimidines such as UFT (litegafur +4:uracil) and 5'-DFUR (doxifluridine) might not reduce the risk of recurrence in colorectal cancer with mesenteric lymph nodes involvement.