The benefit of post-operative adjuvant chemotherapy using oral fluoropyrimidines in rectal cancer

Recent meta-analysis has shown that oral fluoropyrimidenes is effective as post-operative adjuvant therapy in stage II or III colorectal cancer. However, because the efficacy of oral fluoropyrimidines was expected to be mild, it is important to know patients who respond to this mild chemotherapy for reasonable adjuvant therapy for rectal cancer. To clarify the benefit and problems of the post-operative adjuvant chemotherapy using oral fluoropyrimidines, the clinicopathological data of 169 rectal cancer patients treated with or without the post-operative chemotherapy were analyzed retrospectively. Patients in chemotherapy group (n = 100) underwent curative resection with lymphadenectomy were followed by administration of oral fluoropyrimidine. Other 69 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 tumor which was associated with metastasis of mesenteric lymph node or node belonging to the internal iliac artery, and tumor with lymphatic invasion or venous invasion. Post-operative adjuvant chemotherapy using oral fluoropyrimidines such as UFT and 5'-DFUR might not reduce the risk of recurrence in rectal cancer with metastasis of mesenteric lymph node or node belonging to the internal iliac artery, and with lymphatic permeation and venous invasion.