ABSTRACT
A rapid, robust and sensitive HPLC method for analysis of uracil (U) and dihydrouracil (UH2) in plasma was developed using solid phase extraction and ultraviolet detection. Separation was achieved with a SymmetryShield RP18 column and an Atlantis dC18 column using a 10 mM potassium phosphate buffer as mobile phase. Compounds were eluted within 15 min without interference. Recovery was 80.4 and 80.6% for U and UH2. Calibration curves were linear from 2.5 to 80 ng/mL for U and 6.75 to 200 ng/mL for UH2. The LLQ was, respectively, 2.5 ng/mL for U, and 6.75 ng/mL for UH2. Within-run and between-run precision were less than 5.94% and inaccuracy did not exceed 7.80%. The overall procedure has been applied to correlate UH2/U ratio with dihydropyrimidine dehydrogenase activity in 165 cancer patients.
Subject(s)
Chromatography, High Pressure Liquid/methods , Spectrophotometry, Ultraviolet/methods , Uracil/analogs & derivatives , Uracil/blood , Fluorouracil/administration & dosage , Humans , Reference Standards , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
This study screened large cohorts of node-positive and node-negative breast cancer patients to determine whether the G388R mutation of the FGFR4 gene is a useful prognostic marker for breast cancer as reported by Bange et al in 2002. Node-positive (n=139) and node-negative (n=95) breast cancer cohorts selected for mutation screening were followed up for median periods of 89 and 87 months, respectively. PCR - RFLP analysis was modified to facilitate molecular screening. Curves for disease-free survival were plotted according to the Kaplan - Meier method, and a log-rank test was used for comparisons between groups. Three other nonparametric linear rank-tests particularly suitable for investigating possible relations between G388R mutation and early cancer progression were also used. Kaplan - Meier analysis based on any of the four nonparametric linear rank tests performed for node-positive and node-negative patients was not indicative of disease-free survival time. G388R mutation of the FGFR4 gene is not relevant for breast cancer prognosis.
Subject(s)
Biomarkers, Tumor/analysis , Breast Neoplasms/genetics , Mutation, Missense , Receptors, Fibroblast Growth Factor/genetics , Adult , Aged , Breast Neoplasms/pathology , Cohort Studies , Disease-Free Survival , Female , Fibroblast Growth Factors , Genotype , Humans , Middle Aged , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Prognosis , Receptor, Fibroblast Growth Factor, Type 4 , Signal TransductionABSTRACT
A phase II trial was instigated to investigate the antitumour activity, the safety and the pharmacokinetic parameters of RFS2000, a recently identified oral topoisomerase I inhibitor, given once daily (1.5 mg/m(2)/day) as first-line chemotherapy treatment for patients with advanced glioblastoma multiforme (GBM). Between 9 March and 15 September 2000, 17 patients were entered onto the trial. 15 patients were considered eligible. A total of 49 cycles (range 1-8) were administered. Grade 3-4 toxicity was observed in 5 patients. Neutropenia and thrombocytopenia were common toxicities. Pharmacokinetic analysis showed that 9-nitro camptothecin (9-NC) could be detected in the plasma and is progressively converted into 9-amino-camptothecin (9-AC). The response rate was poor, with 5 patients experiencing tumour stabilisation and 10 progressing. Thus, the results do not support the further evaluation of RFS2000 as a single agent in patients with recurrent GBM.
Subject(s)
Antineoplastic Agents/administration & dosage , Camptothecin/analogs & derivatives , Camptothecin/administration & dosage , Glioblastoma/drug therapy , Administration, Oral , Adult , Aged , Antineoplastic Agents/adverse effects , Antineoplastic Agents/pharmacokinetics , Camptothecin/adverse effects , Camptothecin/pharmacokinetics , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Tomography, X-Ray Computed/methodsABSTRACT
This phase I study was undertaken to define the maximum tolerated dose, the dose-limiting toxicity, and the recommended dose of UFT plus leucovorin and vinorelbine in combination treatment of patients with metastatic breast cancer previously treated with one chemotherapy regimen. The pharmacokinetics of UFT and vinorelbine were also evaluated. Patients were treated with escalating doses of UFT and vinorelbine, given every 4 weeks. At least three patients were treated at each dose level before escalating to the next level. As of September 1, 1999, 22 patients have been treated. Eighteen patients were evaluable for antitumor response. One patient had a complete response (which was obtained after three cycles); four patients had a partial response. The area under the concentration-time curve (AUC0-6 h) of 5-fluorouracil increase was more than dose-proportional. The AUC0-6 h values of fluorouracil were significantly higher than those noted for the four patients who developed dose-limiting toxicity at day 15. The removal of one administration of vinorelbine at dose levels 3 and 4 has allowed for increased UFT dosage and AUC0-6 h of fluorouracil, with no dose-limiting toxicity reported for these patients. No pharmacokinetic interaction between UFT and vinorelbine was observed.
Subject(s)
Antineoplastic Agents, Phytogenic/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Vinblastine/analogs & derivatives , Vinblastine/therapeutic use , Administration, Oral , Adult , Aged , Antineoplastic Agents, Phytogenic/adverse effects , Antineoplastic Agents, Phytogenic/pharmacokinetics , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/pharmacokinetics , Area Under Curve , Breast Neoplasms/pathology , Dose-Response Relationship, Drug , Female , Humans , Injections, Intravenous , Leucovorin/administration & dosage , Middle Aged , Tegafur/administration & dosage , Tegafur/pharmacokinetics , Treatment Outcome , Uracil/administration & dosage , Uracil/pharmacokinetics , Vinblastine/adverse effects , Vinblastine/pharmacokinetics , VinorelbineABSTRACT
OBJECTIVES: The purpose of this study was to examine the interpatient and intrapatient variability of the Michaelis-Menten plasma parameters of 5-fluorouracil administered according to a schedule combining a bolus of 400 mg/m2 followed by 22-hour infusion of 600 mg/m2 for 2 consecutive days. PATIENTS: A pharmacokinetic population approach was used to analyze the data from 21 patients with colorectal cancer. RESULTS: The 5-fluorouracil plasma concentrations versus time were best described by a two-compartment model with nonlinear elimination from the central compartment. The relationships between the pharmacokinetic parameters and patient characteristics were tested. On day 1 the mean values (with interindividual variability as expressed by the coefficient of variation) were 1390 mg x h(-1) (20%), and 5.57 mg x L(-1) (22%) for the maximum rate of elimination, and the half-saturating plasma concentration. The maximum rate of elimination was positively correlated to the body surface area and the percentage of liver involvement by metastatic disease determined by tomodensitometric examination. The model was successfully tested with independent data sets corresponding to other schedules. The analysis of this intrapatient variability showed that the half-saturating plasma concentration increased from day 1 to day 2, especially in the patients with low lymphocyte cell dihydropyrimidine dehydrogenase activity. CONCLUSION: The pharmacokinetic parameters obtained in this study would be useful to predict the 5-fluorouracil plasma concentrations following other schedules of administration of 5-fluorouracil and to study the possible pharmacokinetic interactions between 5-fluorouracil and other drugs.
