Aims: Pharmacokinetic modulating chemotherapy (PMC) is designed to boost high serum 5-fluorouracil (5-FU) concentrations via modulation by uracil. The aim of this study was to evaluate the efficacy of PMC as a second-line chemotherapy for postresectional recurrences of colorectal carcinoma.
Methodology: Thirteen patients with unresectable recurrences of colorectal carcinoma were treated with PMC as the second-line chemotherapy, after 5-FU or its derivatives as the first-line chemotherapy. PMC was initiated with a 400 mg combination of uracil and tegafur daily and a 24-hour continuous intravenous infusion of 600 mg/m(2) 5-FU once weekly. The 5-FU dose was increased as the disease progressed.
Results: Six (46%) of the 13 patients exhibited a partial response (PR) to PMC, based on the RECIST criteria. PR was achieved in 2 of 5, 2 of 5, and 2 of 3 patients undergoing oral administration of 5-FU derivatives, intravenous infusion of 5-FU/l-leucovorin and hepatic-artery infusion of 5-FU, respectively. The median survival time of the 13 patients was 17 months.Grade-2 toxicity was found only in 2 patients.
Conclusions: Because PMC is chronomodulating, it is an effective and safe treatment for recurrent colorectal carcinoma. PMC with a dose increase of 5-FU is recommended as a promising second-line regimen for unresectable colorectal carcinoma resistant to 5-FU.