- Arm I: Beginning 3-8 weeks after definitive surgical resection, patients receive fluorouracil IV continuously for 3 weeks. Beginning 1-2 weeks later, patients receive fluorouracil IV continuously concurrently with radiotherapy 5 days a week for 5.5 weeks. Beginning 3-5 weeks after completion of chemoradiotherapy, patients receive fluorouracil IV continuously for 4 weeks every 6 weeks for 2 courses.