The Efficacy of 5-Fluorouracil plus Low-dose Leucovorin as Postoperative Adjuvant Therapy for Patients with Dukes' Stage B and C Colon Cancer

Lim, Jai Soo; Lee, Hyun Seok; Kim, Se Kyung; Kim, In Chul

Abstract

Colon cancer is a major cause of cancer deaths in Western countries and is increasing rapidly in the East where Western nutrition and life-styles are being adopted. About 75% of the individuals with colon cancer will have a primary surgical resection with the hope of complete tumor eradication. Despite the high resectability rate and a general improvement in therapy, nearly half of all patients with colon cancer still die of metastatic tumor. Over the past three decades, many clinical studies have failed to demonstrate benefits from adjuvant therapy. Recently, new data from several studies have demonstrated delays in tumor recurrence and increase in survival for specific groups of patients. (Objectives) This study was designed to evaluate the efficacy of 5-fluorouracil plus low-dose leucovorin as postoperative adjuvant therapy for patients with Dukes' stage B and C colon cancer. (Methods) Eighty seven patients with surgically resected colon cancer in Dukes' stage B and C from Jan 1991 to Dec 1994 were included in this study and divided into two groups. First group (LF arm) included 53 patients who received combination chemotherapy of 5-FU and low-dose leucovorin following surgical resection of colon cancer and the second group (control arm) included 34 patients who received no adjuvant treatment. 5-FU and low-dose leucovorin chemotherapy consisted of leucovorin 20mg/m2, intravenously, plus 5-FU 400mg/m2, intravenously, on days 1-5 every 4 weeks for 12 cycles. (Results) There were significantly less recurrences and distant failure in LF arm than in the control arm. The 4-year disease-free survival rate was 84.2% in LF arm and 54.5% in control arm(p=0.0074). The 4-year overall survival was 89.7% in LF and 48.4% in control arm(p=0.0005). The suvival differences between LF arm and control arm were significant in Dukes' stage B and C respectively. Age of patients, number of metastatic lymph nodes, histologic differentiation and whether or not patients received 5-FU/Leucovorin chemotherapy, were each found to have prognostic significance. (Conclusions) This study strongly suggests that treatment with 5-FU plus low-dose leucovorin significantly prolongs disease-free survival and results in a significant benefit relative to overall survival in patients with surgically resected Dukes' stage B and C colon cancer.