A randomised comparison between 6 months of bolus fluorouracil/leucovorin and 12 weeks of protracted venous infusion fluorouracil as adjuvant treatment in colorectal cancer

Background: We performed a multicentre randomised trial to compare the efficacy and toxicity of 12 weeks of protracted venous infusion (PVI) 5-fluorouracil (5-FU) against the standard bolus monthly regimen of 5-FU/leucovorin (LV) given for 6 months as adjuvant treatment in colorectal cancer (CRC). Patients and methods: Patients with curatively resected stage II and III CRC were randomly assigned to 5-FU/LV [5-FU 425 mg/m(2) intravenously (i.v.) and LV 20 mg/m(2) i.v. bolus days 1-5 every 28 days for 6 months] or to PVI 5-FU (300 mg/m(2)/day for 12 weeks). Results: Between 1993 and 2003, 801 eligible patients were randomised to 5-FU/LV (n = 404) or PVI 5-FU (n = 397). With a median follow-up of 5.3 years, 231 relapses and 220 deaths have been observed. Five-year relapse-free survival (RFS) was 66.7% [95% confidence interval (CI) 61.6% to 71.3%] and 73.3% (95% CI 68.4% to 77.6%) with bolus 5-FU/LV and PVI 5-FU, respectively [hazard ratio (HR) 0.8; 95% CI 0.62-1.04; P=0.101. Five-year overall survival (OS) was 71.5% (95% CI 66.4% to 75.9%) and 75.7% (95% CI 70.8% to 79.9%) with bolus 5-FU/LV and PVI 5-FU, respectively (HR 0.79; 95% CI 0.61-1.03; P=0.083). There was a significant survival advantage for patients starting adjuvant chemotherapy within 8 weeks (P=0.044). Significantly less diarrhoea, stomatitis, nausea and vomiting, alopecia, lethargy, and neutropenia (all with P <0.0001) were seen with PVI 5-FU. Conclusions: There was no OS difference between the two arms, although PVI 5-FU was associated with a trend towards better RFS and OS compared with bolus 5-FU/LV, as well as significantly less toxicity. Based on our results, the probability of 12 weeks of PVI 5-FU being inferior to 6 months of bolus 5-FU/LV is extremely low (P <0.005), and therefore shorter duration of adjuvant treatment should be explored further.