Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024623 (gastric cancer)
 36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The predictive values of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) gene expressions were retrospectively evaluated in patients with gastric cancer treated by a regimen containing S-1. The study population consisted of 53 patients registered into different two phase II studies for metastatic gastric cancer; 27 patients treated by S-1-alone study: 26 patients treated with S-1 combined with irinotecan (CPT-11). TS and DPD gene expressions in primary tumours were measured by the real-time reverse transcription PCR method. There was no statistical difference in DPD gene expression in terms of response in cases treated with S-1 alone and those treated with S-1 plus CPT-11. TS mRNA of responding tumours was lower than that of nonresponding ones when treated with S-1 (P<0.005). In the S-1-alone group, taking TS cutoff as the median values, the response rate in the low TS group was 50%, but only 8% in the high TS group (P<0.05). Patients with low TS gene expression survived longer than those with high TS gene expression (P<0.0001). However, there was no statistically significant difference in response rate and survival between patients with low TS tumours and those with high TS tumours, when the cutoff was taken as the median value of TS gene expression in the group treated with S-1 plus CPT-11. In conclusion, treatment effects of S-1 monotherapy for gastric cancer were determined by the status of TS gene expression, regardless of DPD gene expression. TS predictive power was overcome by CPT-11 combination therapy with S-1.
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PMID:Thymidylate synthase predictive power is overcome by irinotecan combination therapy with S-1 for gastric cancer. 1535 15

There is no chemotherapy considered to be standard treatment for advanced gastric cancer worldwide, and there is no consensus as to whether combination or single agent therapy is preferred. In the phase I portion, a dose-escalation study of cisplatin (CDDP) combined with TS-1, new oral dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine, was performed to determine the maximum-tolerated dose (MTD), recommended dose (RD), dose-limiting toxicities (DLTs), and objective response rate (RR) in advanced gastric cancer (AGC). TS-1 was given orally at 40 mg/m2 bid for 21 consecutive days following a 2-week rest. CDDP was planned to be given intravenously on day 8, at a dose of 60, 70, or 80 mg/m2, depending on the DLT. Treatment was repeated every 5 weeks, unless disease progression was observed. In the phase I portion, the MTD of CDDP was presumed to be 70 mg/m2, because 33.3% of patients (2/6) developed DLTs; mainly neutropenia. Therefore, the RD of CDDP was estimated as 60 mg/m2. In the phase II portion, 19 patients including 6 patients of the RD phase I portion were evaluated. The median administered courses was 4 (range: 1-8). The incidence of haematological and non-haematological toxicities (> or = grade 3) was 15.8 and 26.3%, respectively, but all were manageable. The RR was 74% (14/19, 95%) confidence interval: 54.9 (90.6%), and the median survival days were 383. This regimen is considered to be active against AGC with acceptable toxicity. In addition, currently, a randomized phase III study (JCOG 9912) for AGC patients not treated previously with chemotherapy is underway in Japan. It compares three arms: 5-FU alone, TS-1 alone and CPT-11 with CDDP therapy. We also initiated a randomized phase III study comparing TS-1 alone, and with CDDP for AGC. From those two phase III studies, we may be able to evaluate the clinical benefit of TS-1 in combination with CDDP versus TS-1 single, or 5-FU combined with CDDP therapy in terms of survival benefits and improving the QOL for AGC patients.
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PMID:[Combination chemotherapy of TS-1 +cisplatin for inoperable gastric cancer]. 1557 Sep 20

Metabolizing enzymes such as thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) have long been known to be useful for predicting response and outcome in patients receiving 5-fluorouracil (5-FU). However, few studies have examined the cancerous tissue levels of 5-fluorodeoxyuridine 5'-monophosphate (FdUMP), a metabolite of 5-FU that has an important role in inhibiting DNA synthesis. In this study, for the first time to our knowledge, we measured concentrations of FdUMP in tumor specimens and surrounding non-cancerous tissue obtained at operation in 10 patients with gastric cancer who received TS-1 before surgery (80 mg/m2, 3 days). The FdUMP level in the cancerous tissue was significantly higher than that in the non-cancerous tissue (153.0 +/- 85.7 pmol/g tissue vs. 53.0 +/- 47.0 pmol/g tissue)(p = 0.0046). Furthermore, the TS level in tumor was significantly higher than that in non-cancerous tissue (6.362 +/- 5.106 pmol/g tissue vs. 2.092 +/- 2.050 pmol/g tissue) (p = 0.0310). The mean ratios of TS-bound FdUMP to TS and FdUMP concentrations in the cancerous tissues were 45.9% and 2.00%, respectively. Our results demonstrate that in cancerous tissue, TS-1 may produce high FdUMP concentration and suppress about half FdUMP concentration by forming ternary complexes.
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PMID:Level of 5-fluorodeoxyuridine 5'-monophosphate in cancerous tissue in patients with gastric cancer under preoperative administration of TS-1. A preliminary study. 1627 May 33

We have recently demonstrated in a Phase I/II study that combination chemotherapy with docetaxel (TXT) and S-1 is active against metastatic gastric carcinomas. To elucidate the mechanisms underlying the synergistic effects of these drugs, both the growth inhibitory effects and the expression profiles of enzymes involved in fluorouracil (5-FU) metabolism were examined in vitro and in vivo. TXT alone and in combination with 5-FU inhibited the growth of each of the 5 gastric cancer cell lines that we examined (TMK-1, and MKN-1, -28, -45 and -74), in a time- and dose-dependent manner. Moreover, striking synergistic effects were observed in TMK-1 cells in vitro with IC50 values of between 4.73 and 0.61 nM 5-FU. Furthermore, in TMK-1 xenografts, 5-FU/TXT cotreatments exhibited synergistic antitumor effects. The combination of S-1 and TXT, however, exhibited greater growth-inhibitory effects than the 5-FU/TXT cotreatments. The mechanisms underlying these synergistic effects of S-1 and TXT were examined by expression and activity analyses of the 5-FU metabolic enzymes. The expression of thymidylate synthase (TS), and dihydropyrimidine dehydrogenase (DPD) were decreased 50 and 73% of control levels, respectively, and that of orotate phosphorybosyl transferase (OPRT) was increased by 3.9-fold at the protein level. These findings suggested that biochemical modulation of the 2 drugs had occurred, which was further confirmed by the results of the activity assays. These data strongly indicate that a combination chemotherapy of TXT and S-1 is effective against gastric carcinomas and is therefore a good candidate as a standard chemotherapeutic strategy in treating these tumors.
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PMID:Synergistic effects of docetaxel and S-1 by modulating the expression of metabolic enzymes of 5-fluorouracil in human gastric cancer cell lines. 1655 85

A dose-escalation study of irinotecan (CPT-11) combined with S-1, an oral dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine, was performed to determine the maximum-tolerated dose (MTD), recommended dose (RD), dose-limiting toxicities (DLTs), and objective response rate (RR) in advanced gastric cancer (AGC). S-1 was administered orally at 80 mg m-2 day-1 from day 1 to 14 of a 28-day cycle and CPT-11 was given intravenously on day 1 and 8 at an initial dose of 70 mg m-2 day-1, stepping up to 100 mg m-2. The treatment was repeated every 4 weeks, unless disease progression was observed. In the phase I portion, the MTD of CPT-11 was presumed to be 100 mg m-2, because 66.6% of patients (two of three) developed DLTs. All three patients at the initial RD of CPT-11 (90 mg m-2) experienced grade 4 haematological or grade 3 nonhaematological toxicities at second course, followed by the dose reduction of CPT-11 from the third course. Considering safety and the ability to continue treatment, the final RD was determined to be 80 mg m-2. In the phase II portion, 42 patients including seven patients in the final RD phase I portion were evaluated. The median treatment course was five (range: 1-13). The incidences of severe (grade 3-4) haematological and nonhaematological toxicities were 19 and 10%, respectively, but all were manageable. The RR was 62% (26 of 42, 95% confidence interval: 47.2-76.6%), and the median survival time was 444 days. Our phase I/II trial showed S-1 combined with CPT-11 is effective for AGC and is well tolerated, with acceptable toxicity.
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PMID:Phase I/II study of S-1 combined with irinotecan for metastatic advanced gastric cancer. 1657 38

We evaluated the expression of 5-FU pathway genes in prechemotherapeutic fresh frozen samples obtained from primary tumors to predict response and survival of 59 metastatic gastric cancer patients treated with S-1 monotherapy as first line treatment. Five 5-FU pathway genes, including thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyltransferase (OPRT), thymidine phosphorylase (TP) and uridine phosphorylase (UP), were analyzed by the quantitative real-time reverse transcriptional PCR method. Median values of each gene were selected for cut-off values separating high and low gene expressions. In univariate analyses, low TS, high OPRT and low TP were significantly associated with a tumor shrinkage and a long survival, whereas DPD and UP gene expressions did not correlate with response and survival. Multivariate analyses revealed that independent variables were OPRT and TS for response and TS and TP for survival. When OPRT and TS were combined, a significantly increased accuracy rate of 91.5% was seen for response. Similarly, an increased hazard ratio of 10.29 was observed for survival in patients possessing low TS and low TP, compared with those with high TS or high TP. The simple combinations of 2 genes, OPRT and TS for response and TS and TP for survival, may allow identification of gastric cancer patients who will benefit from S-1 chemotherapy.
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PMID:Simple combinations of 5-FU pathway genes predict the outcome of metastatic gastric cancer patients treated by S-1. 1673 97

S-1 is an attractive oral fluorouracil antitumor drug, which is being called "a self-rescuing drug". This novel oral fluoropyrimidine is combined with three pharmacological agents: tegafur (FT) which is a prodrug of 5-fluorouracil (5-FU), 5-chloro-2,4-dihydroxypyridine (CDHP) which inhibits dihydropyrimidine dehydrogenase (DPD) activity, and potassium oxonate (Oxo) which reduces gastrointestinal toxicity. Phase I and an early phase II clinical trials were performed about ten years ago, and these results had already been introduced to the Journal "Clinical Cancer Research Vol. 5, pages 2000-2005, 1999". The data of this article in this journal was referred from the results of the figures and tables based on the above trial. Most of the authors in this article have contributed on that pharmacokinetics study and published the above manuscripts. In that study, the pharmacokinetics of 5-FU, intact FT, CDHP and Oxo after administration of the standard dose of S-1 had been performed. These studies were carried out at two hospitals, Department of Surgery (Section 1) Sapporo Medical University and Chemotherapy Cancer Center, Cancer Institute Hospital and Japanese Foundation for Cancer Research (Ohtsuka). The number of patients accepted for this trial is twelve, 5 patients with gastric cancer, 4 with colorectal cancer and 3 with breast cancer. Single administration trial was referred to all patients, but consecutive administration trial was limited to ten patients. The results of plasma concentration, Cmax, Tmax, AUC0-14, and T1/2 of 5-FU, FT, CDHP, and Oxo were ascertained in details. It was a surprise that the indicated data was very similar to that of the intravenous 5-FU continuous infusion. Therefore, the low dose administration of 5-FU (FT) as S-1 may result in good antitumor effects with minimum adverse effects to the patients.
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PMID:[Pharmacokinetics of S-1]. 1689 69

The pharmacokinetics and pharmacodynamics of oral S-1, a dihydropyrimidine dehydrogenase (DPD) inhibitory fluoropyrimidine, were compared with those of protracted venous infusion (PVI) of 5-fluorouracil (5-FU). In all, 10 patients with gastric cancer received PVI of 5-FU at a dose of 250 mg/m2/day for 5 days. After a washout period of 9 days, the 10 patients received two divided doses daily for 28 days. S-1 was administered orally at about 9 a.m. and 7 p.m. Plasma concentrations of 5-FU and F-beta-alanine (FBAL) were measured for pharmacokinetic analysis, and the plasma uracil concentration was monitored as a surrogate marker of DPD inhibition in the same 10 patients on days 1-5 of PVI of 5-FU and on days 1-5 of oral S-1. The area under the curve (AUC0-10h) of 5-FU on day 5 was 728 +/- 113 ng x hr/ml for PVI of 5-FU and 1,364 +/- 374 ng x hr/ml for S-1. The median 5-FU PVI: S-1 ratio of the AUC0-10h of 5-FU was 1.9. The AUC0-10h of FBAL on day 5 of PVI of 5-FU was 9,465 +/- 3,225 ng x hr/ml, AUC0-10h, as compared with 1,725 +/- 605 ng x hr/ml on day 5 of S-1 treatment. The AUC0-10h of uracil on day 5 was 252 +/- 60 ng x hr/ml with PVI of 5-FU and 12,582 +/- 3,060 ng x hr/ml with S-1. The AUC0-10h of FBAL was markedly lower and plasma uracil concentrations were significantly higher for S-1 than for PVI of 5-FU, clearly demonstrating the effect of DPD inhibition.
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PMID:[Plasma concentrations of 5-fluorouracil and F-beta-alanine following oral administration of S-1, a dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine, as compared with protracted venous infusion of 5-fluorouracil]. 1689 70

In the present article, we have summarized the phase I/II clinical trials on combination therapy of S-1 and docetaxel. With result of the phase I study, patients were treated with intravenous infusion of 40 mg/m2 docetaxel on day 1 and oral S-1 80 mg/m2/day on days 1 to 14 every 3 weeks. Forty eight patients received a total of 272 treatment cycles. No complete responses (CRs) and 27 partial responses (PRs) were observed for an overall response rate (CR+PR) of 56.2% (95% CI, 38-66%). Eighteen patients (37.5%) had stable disease (SD), and 3 patients (6.2%) had progressive disease (PD) as best response. The tumor control rate (CR+PR+SD) was 93.8% (95% CI, 83-98%). The median overall survival was 14.3 months (95% CI: 10.7-20.3 months) and the median time to tumor progression was 7.3 months (95% CI: 4.2-10.7 months). The most common grade 3-4 hematologic toxicities were neutropenia 58.3%, leukopenia 41.7%, febrile neutropenia 8.3%, and anemia 8.3%. The most common grade 3 nonhematologic toxicities were anorexia 14.6%, stomatitis 8.3%, nausea 6.3%, diarrhea 4.2%, constipation 4.2%, and vomiting 2.1%. No grade 4 nonhematologic toxicities were reported, and all treatment-related toxicities were resolved. The mechanisms underlying these synergistic effects of S-1 and docetaxel were examined by expression and activity analyses of 5-FU metabolic enzymes. The expressions of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) were decreased and that of orotate phosphorybosyl transferase (OPRT) was increased in mRNA, protein level and activity assay after the treatment with docetaxel and 5-FU in the TMK-1 gastric cancer cell. These findings strongly indicate that the combination chemotherapy of docetaxel and S-1 is effective against gastric carcinomas and therefore is a good candidate as a standard chemotherapeutic strategy in treating these tumors.
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PMID:[Combination chemotherapy of S-1 and docetaxel on advanced and recurrent gastric cancer]. 1689 78

Therapy for patients with advanced gastric cancer is not satisfactory. The median survival of patients with advanced gastric cancer is approximately 6-9 months and less than 10% of patients survive one year. Despite identification of new classes of agents, such as camptothecins, taxanes, and new platinum analogs, the improvement has been limited and therapy intensive resulting in considerable morbidity. More intensive therapies are challenging not only for the patients and their relatives but also for the health care providers. Oral fluropyrimidines like capecitabine and S-1 have generated considerable interest because of convenience and their activity against gastric carcinoma. S-1 is of significant interest because of many studies in Japan in gastric cancer patients demonstrating its substantial activity as a single agent and in combination with other agents. Furthermore, S-1 represents a fourth generation "designer" drug. It has a component that enhances the cytotoxic activity of tegafur by inhibiting dihydropyrimidine dehydrogenase (DPD) and also has a component that reduces phosphorylation of 5-fluorouracil in the gastrointestinal tract to potentially reduce toxicity. This unique combination is rarely found in an oral agent. In addition, considerable ethnic differences in the tolerated doses of S-1 have been considered related to varying efficiency rates of conversion of tegafur to 5-fluorouracil by the CYP450 enzyme system. The varying efficiency is thought to be due to the presence of certain polymorphisms in the CYP2A6 gene responsible for metabolizing tegafur to 5-fluorouracil. S-1 is under rapid development in the West for gastric carcinoma. Phase I/II studies of the combination of S-1 plus cisplatin have been completed and a global phase III study, accruing rapidly, is comparing S-1 plus cisplatin to 5-fluorouracil plus cisplatin (a reference regimen).
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PMID:Rapid development of S-1 in the west for therapy of advanced gastric carcinoma. 1689 85


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