A phase I-II study of oral doxifluridine plus radiotherapy in radiosensitive tumors of the pelvic region

Aims and backroundFluoropyrimidines have shown synergic effects in combination with radiotherapy in several tumor types. Doxifluridine is a novel 5-fluorouracil (5-FU) prodrug which is transformed into 5-FU in neoplastic tissue. This would imply enhancement of radiotherapy by 5-FU in neoplastic tissue, where the drug is concentrated higher than in surrounding healthy tissues.MethodsA phase I-II study was carried out on 10 patients with radiosensitive tumors of the pelvic area (4 uterine carcinomas). Escalating doses of oral doxifluridine were administered in combination with standard radiotherapy to assess the efficacy and toxicity profile of the combined treatment. The 9 evaluable patients (3 groups of 3 patients each) received oral doxifluridine, at daily doses of 500, 750, or 1000 mg, for 6 consecutive weeks in combination with a standard (1.8-2.0 Gy) dose of radiotherapy. Assessment of physical and laboratory parameters was made at baseline, then weekly up to the end of the treatment and at follow-up....