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Both gene expression for orotate phosphoribosyltransferase and its ratio to dihydropyrimidine dehydrogenase influence outcome following fluoropyrimidine-based chemotherapy for metastatic colorectal cancer.

ABSTRACT: Activation of 5-fluorouracil into its nucleotides requires phosphorylation by three pathways involving orotate phosphoribosyl-transferase (OPRT), uridine phosphorylase (UP), or thymidine phosphorylase (TP). In this study, we investigated the association between gene expressions of these three enzymes and antitumour effect. Gene expressions in primary colorectal tumours were analysed by a real-time reverse transcriptional-polymerase chain reaction method in 37 patients receiving oral treatment of tegafur-uracil and leucovorin for metastatic diseases. The median values of OPRT mRNA expressions were 1.39 and 0.85 for responding tumours and nonresponding tumours, respectively, showing a statistically significant difference (P=0.0008). Responding tumours had statistically lower expressions of TP mRNA than nonresponding tumours (P=0.006). However, there was no difference in UP mRNA expression between responding and nonresponding tumours. Patients with high OPRT (>/=1.0) gene expression survived longer than those with low OPRT (<1.0) expression. Dihydropyrimidine dehydrogenase (DPD) gene expressions were measured. Responding tumours had a statistically higher OPRT/DPD ratio than the nonresponding ones (P=0.003). When the median value of the OPRT/DPD ratio was selected as the cutoff value, patients with a high OPRT/DPD ratio survived statistically longer than those with a low ratio (P=0.0014). In conclusion, both the expression of OPRT gene and the OPRT/DPD ratio might be useful as predictive parameters for the efficacy of fluoropyrimidine-based chemotherapy for metastatic colorectal cancer.

SUBMITTER: Ichikawa W

PROVIDER: S-EPMC2394351 | biostudies-other | 2003 Oct

REPOSITORIES: biostudies-other

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Project description:PurposeThe degree of benefit from palliative chemotherapy differs widely among patients with metastatic esophageal squamous cell carcinoma (MESCC). The purpose of this study was to develop and validate a prognostic nomogram to predict survival and aid physicians and patients in the decision-making process regarding treatment options.Materials and methodsClinicopathologic variables and treatment outcomes of 239 patients who were diagnosed with MESCC and received either fluorouracil/cisplatin (FP) or capecitabine/cisplatin (XP) as first-line chemotherapy were reviewed. A nomogram was developed as a prognostic scoring system incorporating significant clinical and laboratory variables based on a multivariate Cox proportional hazards regression model. An independent series of 61 MESCC patients treated with FP served as an independent data set for nomogram validation.ResultsNo difference in response rate was observed between the FP group (44.8%) and the XP group (54.2%). Similarly, no significant differences in median progression-free survival and median overall survival were observed between regimen groups. Multivariate analysis showed that poor performance status (Eastern Cooperative Oncology Group [ECOG] status≥2), weight loss (10% of the weight loss for 3 months), low albumin level (≤3.5 g/dL), and absence of previous esophagectomy at the time of chemotherapy were significantly associated with low OS in both groups (p<0.05). Based on these findings, patients were classified into favorable (score, 0 to 90), intermediate (91-134), and poor (>135) prognostic groups. The median survival for those with a favorable ECOG was 13.8 months (95% confidence interval [CI], 10.8 to 18.6 months), for intermediate 11.2 months (95% CI, 8.7 to 11.9 months), and for poor, 7.0 months (95% CI, 3.6 to 10.0 months). External validation of the nomogram in a different patient cohort yielded significantly similar findings.ConclusionThe nomogram described here predicts survival in MESCC patients and could serve as a guide for the use of FP/XP chemotherapy in MESCC patients.

Project description:Background:The fluoropyrimidine drug 5-Fluorouracil (5-FU) and the prodrug capecitabine have been extensively used for treatment of many types of cancer including colorectal, gastric, head and neck. Approximately, 10 to 25% of patients suffer from severe fluoropyrimidine-induced toxicity. This may lead to dose reduction and treatment discontinuation. Pharmacogenetics research could be useful for the identification of predictive markers in chemotherapy treatment. The aim of the study was to investigate the role of five genetic polymorphisms within two genes (DPYD, TYMS) in toxicity and efficacy of fluoropyrimidine-based chemotherapy. Methods:Total genomic DNA was extracted from 83 cancer patients treated with fluoropyrimidine-based chemotherapy. In this study, three polymorphisms were genotyped in dihydropyrimidine dehydrogenase gene c.1905+1 G>A (DPYD*2A; rs3918290), c.1679 T>G (I560S; DPYD*13; rs55886062), and c.2846A>T (D949V; rs67376798) and two polymorphisms, besides the Variable Number of Tandem Repeat (VNTR) polymorphism and 6-bp insertion/deletion polymorphism in thymidylate synthase gene. The analysis of polymorphisms for rs3918290, rs55886062, rs67376798 and 6-bp insertion/deletion in TYMS was done by Polymerase Chain Reaction-restriction Fragment Length Polymorphism (PCRRFLP) TYMS VNTR analysis. 5-FU-related toxicities such as anemia, febrile neutropenia, neurotoxicity, vomiting, nausea, and mucositis were evaluated according to NCI-CTC criteria version 4.0. T-test and chi-square were used and p-values less than 0.05 were considered statistically significant. Results:DPYD gene polymorphisms were not observed in this study. The frequency of the TYMS +6 bp allele was 40.35% and the -6 bp allele was 59.65% in this study. The frequency of VNTR 2R allele was 48.75% and 3R allele was 51.15%. Toxicity grade II diarrhea, mucositis, nausea, vomiting, and neurotoxicity was 2.2, 24.1, 15.7, 6, and 51.8%, respectively. Thymidylate synthase ins/del polymorphisms were associated with increased grade III neurotoxicity (p=0.02). Furthermore, anemia grade III was significantly associated with 2R/2R genotype (0.009). Conclusion:Thymidylate synthase gene polymorphisms may play a key role in fluoropyrimidne -based chemotherapy. Although rare DPYD polymorphisms were not observed in our study, according to large population studies, DPYD gene polymorphisms could be used as a predictive biomarker for patient treatments.

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Both gene expression for orotate phosphoribosyltransferase and its ratio to dihydropyrimidine dehydrogenase influence outcome following fluoropyrimidine-based chemotherapy for metastatic colorectal cancer.

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