Phase II study of weekly high dose fluorouracil in previously treated patients, with metastatic colorectal cancer

The purpose of this study was to evaluate the efficacy, toxicity, and safety of outpatient chemotherapy with weekly high-dose 5-fluorouracil (HD- 5FU) in previously treated patients (pts) with metastatic colorectal cancer. Previously treated and failed pts with histologically confirmed, measurable metastatic colorectal cancer, performance status (WHO) 0-2 and adequate bone marrow function were eligible for treatment. Patients received 5FU-(2.6 g/m²) as a 24-hour continuous infusion. Treatment was repeated weekly. A total of 202 cycles were given. Eighteen pts were enrolled. No pts achieved objective response. In 6 pts (33%), after 4 weeks of treatments, CEA level decreased 25% or more, and after 8 weekly treatments it rose again. Mild myelosuppression rarely occurred. Grade 1 nausea and vomiting occurred in 2 pts and Grade 1 diarrhea occurred in 2 pts. Mucositis was not observed. Conclusion: In our experience single agent, weekly, high dose 5-FU is well tolerated, but is ineffective as second-line treatment for metastatic colorectal cancer, and has only a marginal effect on CEA level.