UMLS:C0027947 - FACTA Search

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Query: UMLS:C0027947 (neutropenia)
17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The objectives of the present study were (i) to study the pharmacogenetics of UGT1A1*6, UGT1A1*28 and ABCG2 c.421C>A in three distinct healthy Asian populations (Chinese, Malays and Indians), and (ii) to investigate the polygenic influence of these polymorphic variants in irinotecan-induced neutropenia in Asian cancer patients. Pharmacokinetic and pharmacogenetic analyses were done after administration of irinotecan as a 90-min intravenous infusion of 375 mg/m(2) once every 3 weeks (n = 45). Genotypic-phenotypic correlates showed a non-significant influence of UGT1A1*28 and ABCG2 c.421C>A polymorphisms on the pharmacokinetics of SN-38 (P > 0.05), as well as severity of neutropenia (P > 0.05). Significantly higher exposure levels to SN-38 (P = 0.018), lower relative extent of glucuronidation (REG; P = 0.006) and higher biliary index (BI; P = 0.003) were found in cancer patients homozygous for the UGT1A1*6 allele compared with patients harboring the reference genotype. The mean absolute neutrophil count (ANC) was 85% lower and the prevalence of grade 4 neutropenia (ANC < or = 500/microL) was 27% in patients homozygous for UGT1A1*6 compared with the reference group. Furthermore, the presence of the UGT1A1*6 allele was associated with an approximately 3-fold increased risk of developing severe grade 4 neutropenia compared with patients harboring the reference genotype. These exploratory findings suggest that homozygosity for UGT1A1*6 allele may be associated with altered SN-38 disposition and may increase the risk of severe neutropenia in Asian cancer patients, particularly in the Chinese cancer patients who comprised 80% (n = 36) of the patient population in the present study.
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PMID:Role of UGT1A1*6, UGT1A1*28 and ABCG2 c.421C>A polymorphisms in irinotecan-induced neutropenia in Asian cancer patients. 1762 17

The pharmacokinetics of irinotecan and its metabolites has been widely studied. No pharmacokinetic data, however, are available in haemodialysis patients. We report two clinical cases of severe toxicity, one of which was fatal, in two haemodialysis patients treated with irinotecan for a metastatic colorectal cancer. In case no. 1, M.S., aged 71 years, was treated with first-line FOLFIRI chemotherapy (irinotecan 180 mg/m) for local recurrence with liver metastases of a colon cancer treated with an LV5FU2 protocol as an adjuvant therapy 3 years previously. After the first cycle of irinotecan, the patient presented grade 4 diarrhoea on day 9, then a febrile grade 4 neutropenia on day 14 leading to his death on day 18. In case no. 2, M.D., aged 57 years, was treated successively by radiochemotherapy with an LV5FU2 regimen, then with four cycles of FOLFIRI (irinotecan at 125 mg/m) and finally with the cetuximab/irinotecan combination using the conventional dosage. Febrile neutropenia was observed on day 10 of the first irinotecan infusion with a dose of 180 mg/m and on day 8 of the second infusion with a lower dose of 120 mg/m. The patient's general condition progressively deteriorated with the advancement of the neoplastic disease, which led ultimately to his death. In this patient, plasma concentrations of irinotecan and its metabolite, SN-38, were measured during the course of the first FOLFIRI cycle on day 2 and on day 4, before and after dialysis sessions. The observed results suggest that, although irinotecan is partially dialysable, SN-38 is not. In conclusion, dose recommendations have to be defined in haemodialysis patients with renal dysfunction owing to the potential toxicity of irinotecan in these patients. Special care should be taken in liver metastasis cases owing to the nondialysability of SN-38.
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PMID:Irinotecan-based chemotherapy in a metastatic colorectal cancer patient under haemodialysis for chronic renal dysfunction: two cases considered. 1766 6

The hepatic isoform 1A1 of uridine diphosphate glucuronosyltransferase is responsible for glucuronidation and detoxification of SN-38, the active metabolite of irinotecan. The presence of an additional TA repeat in the TATA sequence of the UGT1A1 promoter leads to a significant decrease in SN-38 glucuronidation. Patients with the UGT1A1 (TA)7 allele are more likely to experience severe neutropenia and diarrhea following irinotecan chemotherapy. We assessed the distribution of the UGT1A1 (TA)n polymorphism in healthy male and female US residents of European and Asian descent. We used a fluorescent polymerase chain reaction-based assay to detect UGT1A1 (TA)n polymorphisms in 138 healthy volunteers (56 Caucasians, 37 Chinese, 37 Filipino and eight Japanese) between the ages of 18 and 65 years. The chi-test was used to assess between-group differences in the distribution of UGT1A1 (TA)n genotypes. The UGT1A1 (TA)6/6 genotype was significantly more common in Asians than in Caucasians (76 vs. 46%), whereas the (TA)6/7 (39 vs. 20%) and (TA)7/7 (13 vs. 5%) genotypes were more common in Caucasians than in Asians. Genotype distributions did not differ significantly between men and women in either group. The UGT1A1 (TA)5/5 genotype was detected in one Caucasian woman. In conclusion, consistent with previous reports, the UGT1A1 (TA)7/7 genotype was significantly more common in Caucasians than in Asians. UGT1A1 (TA)n/n genotype distribution did not vary with sex in individuals of European or Asian descent.
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PMID:Distribution of the UGT1A1*28 polymorphism in Caucasian and Asian populations in the US: a genomic analysis of 138 healthy individuals. 1776 98

To investigate whether the OATP1B1 polymorphisms affect irinotecan-pharmacokinetics and subsequent toxicity and tumor response of patients with advanced NSCLC. A total of 81 Korean NSCLC patients enrolled in a phase II study of irinotecan and cisplatin chemotherapy were genotyped for OATP1B1 -11187G>A, 388A>G and 521T>C variants. The 521TC or CC and -11187AA genotypes were associated with higher AUC(SN-38) (p=0.016 and 0.030, respectively). When haplotypes were assigned, patients with *15 haplotype showed significantly higher AUC(SN-38) than *1a or *1b haplotypes (p=0.006). Grade 4 neutropenia was associated with the 521TC or CC genotypes, whereas, grade 3 diarrhea was associated with 388GG genotype (p=0.046). Of the 81 patients enrolled, 77 were assessable for response and 36 (47%) patients achieved partial responses (PR). However, no statistical significance was observed between genotype and response. These findings suggest that OATP1B1 variants are involved in SN-38 disposition and highly predictive for severe toxicity of NSCLC patients treated with irinotecan-based chemotherapy.
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PMID:Influence of the organic anion-transporting polypeptide 1B1 (OATP1B1) polymorphisms on irinotecan-pharmacokinetics and clinical outcome of patients with advanced non-small cell lung cancer. 1776 2

Irinotecan is used widely in the treatment of several malignancies, but unpredictable severe toxicities such as myelosuppression and delayed-type diarrhea are sometimes experienced. Polymorphism of the UGT1A1 gene is one of the likely reasons for interindividual differences in irinotecan pharmacokinetics and severe toxicity. Also, polymorphic organic anion-transporting polypeptide 1B1 (OATP1B1, SLCO1B1) is reported to be involved in the hepatocellular uptake of SN-38. A 61-year-old man with lung cancer developed severe toxicities, including grade 3 diarrhea, grade 4 leukopenia, and grade 4 neutropenia, after the first cycle of irinotecan (60 mg/m) plus cisplatin chemotherapy. The irinotecan and SN-38 areas under the concentration-time curve from time zero to infinity in this patient were 43% and 87% higher than the corresponding mean values for 10 other patients with lung cancer treated with irinotecan (60-100 mg/m) normalized for the dose of irinotecan. Analysis of genetic variants in genes encoding the drug-metabolizing enzyme (UGT1A1) and transporter (SLCO1B1) involving irinotecan disposition revealed that this patient was homozygous for the SLCO1B1*15 allele, which may result in severe toxicities attributable to the extensive accumulation of SN-38. Screening of SLCO1B1*15 is suggested to be useful in irinotecan chemotherapy to avoid unpredicted severe toxicity, although the homozygous genotype is rare among the Japanese.
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PMID:Severe toxicities after irinotecan-based chemotherapy in a patient with lung cancer: a homozygote for the SLCO1B1*15 allele. 1789 62

To define an integrated pharmacogenetic model for predicting irinotecan pharmacokinetic (PK) and severe toxicity, we evaluated multivariate analysis using 15 polymorphisms within seven genes with putative influence on metabolism and transport of irinotecan. A total of 107 NSCLC patients treated with irinotecan were evaluated for PK and genotyped for the UGT1A1*6, UGT1A1*28, UGT1A9*22, ABCB11236C>T, 2677G>T/A, 3435C>T, ABCC2-24C>T, 1249G>A, 3972C>T, ABCG234G>A, 421C>A, and SLCO1B1 -11187G>A, 388A>G, and 521T>C, and CYP3A5*3 polymorphisms. Multivariate linear and logistic regression analyses including genotypes and clinicopathologic factors were performed. SN-38 AUC was significantly correlated with ANCs (r=-0.3, p=0.009) and grade 4 neutropenia (p=0.01). The UGT1A1*6/*6, UGT1A9*1/*1 or *1/*22, and SLCO1B1 521TC or CC genotypes, and female-gender were predictive for higher AUC(SN-38) in multivariate analysis. Among them, SLCO1B1 521TC or CC and UGT1A1*6/*6 genotypes were independently predictive for grade 4 neutropenia in multivariate analysis (OR=3.8 and 7.4, respectively). Although no significant association was observed between PK parameters and grade 3 diarrhea, UGT1A9*1/*1, ABCC23972CC, and ABCG234GA or AA genotypes were independently predictive for grade 3 diarrhea in multivariate analysis (OR=6.3, 5.6, and 5.1, respectively). Patient selection based on integrated pharmacogenetic model would be helpful for predicting irinotecan-PK and severe toxicities in NSCLC patients.
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PMID:Integrated pharmacogenetic prediction of irinotecan pharmacokinetics and toxicity in patients with advanced non-small cell lung cancer. 1822 20

Irinotecan is widely used in the treatment of colorectal, gastric, and lung cancers. However, adverse drug reactions such as severe diarrhea and neutropenia limit the dose of this drug. Irinotecan is metabolized by carboxylesterase to form an active metabolite, 7-ethyl-10-hydroxycamptothecin(SN-38), which in turn is subsequently conjugated by UGT-glucuronosyltransferase 1A1(UGT1A1)to yield an inactive form, SN-38 glucuronide(SN-38 G). The UGT1A1 gene polymorphisms contribute to the individual variation in adverse events among patients administered irinotecan. However, the distribution of polymorphisms shows large interethnic differences. The distribution of UGT1A1*28 greatly differs between Caucasians and Japanese; the frequency of UGT1A1*28 is high in Caucasians, whereas it is low in Asians including Japanese. Recently, it has been demonstrated that genetic variants of UGT1A1*6 in addition to UGT1A1*28 are associated with the occurrence of adverse events in irinotecan chemotherapy in Asians. This review summarizes recent studies to outline the role of UGT1A1*28 and UGT1A1*6 for irinotecan-induced adverse drug reaction in Japanese cancer patients.
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PMID:[Role of UGT1A1*28 and UGT1A1*6 for irinotecan-induced adverse drug reaction]. 1863 45

This phase II study investigated the recommended dose (RD) of irinotecan (CPT-11) by dose escalation in elderly (>or=70 years) chemotherapy-naive Japanese patients with advanced non-small cell lung cancer. UGT1A1*28 and *6 polymorphisms and pharmacokinetics were also investigated. Thirty-seven patients received the RD, 100 mg/m(2) of intravenous CPT-11, on days 1 and 8 of each 3-week cycle in phase II. The overall response rate was 8.1%. The median survival time was 441 days, and time to progression was 132 days. A significant correlation was observed between the incidence of grade 3/4 neutropenia and area under the time-concentration curve (AUC) values of SN-38. A reduction in AUC ratios (AUC(SN-38G)/AUC(SN-38)) and a rise in incidence of grade 3/4 neutropenia were observed with increase in polymorphism. The regimen was well tolerated and provided good disease control and promising survival effects. An analysis of the influence of UGT1A1*28 and *6 polymorphisms provides useful information for the prediction of CPT-11-related hematological toxicity.
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PMID:Phase I/II pharmacokinetic and pharmacogenomic study of UGT1A1 polymorphism in elderly patients with advanced non-small cell lung cancer treated with irinotecan. 1868 65

Pharmacogenetic research indicates a relationship between a polymorphism in the gene encoding uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) and irinotecan inactivation, in that degradation of SN-38, the active metabolite of irinotecan, correlates inversely with the number of TA repeats in the TATA element of the UGT1A1 promoter region. Individuals who are homozygous for the UGT1A1*28 allele (7 repeats) may exhibit reduced degradation of SN-38 and increased probability of severe toxicities. Clinical study results, as reported in the literature, have not been uniform, however, in showing a relation between genotype and the development of toxicities. Even when correlations are statistically significant, confidence intervals are wide, rendering assessment of individual risk difficult at best. Irinotecan labeling recommends testing for the UGT1A1*28 allele and reducing irinotecan dosing in patients who are positive to reduce the likelihood of dose-limiting neutropenia only, but not diarrhea. Importantly, both dose-limiting neutropenia and diarrhea are dependent on numerous known and unknown factors, such as the specific regimen used, duration of therapy, doses, cycle of treatment, and complexities of irinotecan pharmacodynamics and pharmacokinetics, including other key enzymes and drug transporters. Guidance on how to modify irinotecan dosing or how to incorporate the impact of multiple variables into clinical decision-making does not exist. Furthermore, pharmacogenomic test results at this time can only provide an estimate of risk for subsets of populations rather than a risk-benefit estimate for an individual. Consequently, these test results are supplementary to clinical judgment, which requires assessing multiple variables that contribute to phenotype to arrive at individual dosing decisions.
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PMID:Irinotecan and uridine diphosphate glucuronosyltransferase 1A1 pharmacogenetics: to test or not to test, that is the question. 1872 Mar 61

This evidence-based review addresses the question of whether testing for UGT1A1 mutations in patients with metastatic colorectal cancer treated with irinotecan leads to improvement in outcomes (e.g., irinotecan toxicity, response to treatment, morbidity, and mortality), when compared with no testing. No studies were identified that addressed this question directly. The quality of evidence on the analytic validity of current UGT1A1 genetic testing methods is adequate (scale: convincing, adequate, inadequate), with available data indicating that both analytic sensitivity and specificity for the common genotypes are high. For clinical validity, the quality of evidence is adequate for studies reporting concentration of the active form of irinotecan (SN-38), presence of severe diarrhea, and presence of severe neutropenia stratified by UGT1A1 common genotypes. The strongest association for a clinical endpoint is for severe neutropenia. Patients homozygous for the *28 allele are 3.5 times more likely to develop severe neutropenia compared with individuals with the wild genotype (risk ratio 3.51; 95% confidence interval 2.03-6.07). The proposed clinical utility of UGT1A1 genotyping would be derived from a reduction in drug-related adverse reactions (benefits) while at the same time avoiding declines in tumor response rate and increases in morbidity/mortality (harms). At least three treatment options for reducing this increased risk have been suggested: modification of the irinotecan regime (e.g., reduce initial dose), use of other drugs, and/or pretreatment with colony-stimulating factors. However, we found no prospective studies that examined these options, particularly whether a reduced dose of irinotecan results in a reduced rate of adverse drug events. This is a major gap in knowledge. Although the quality of evidence on clinical utility is inadequate, two of three reviewed studies (and one published since our initial selection of studies for review) found that individuals homozygous for the *28 allele had improved survival. Three reviewed studies found statistically significant higher tumor response rates among individuals homozygous for the *28 allele. We found little or no direct evidence to assess the benefits and harms of modifying irinotecan regimens for patients with colorectal cancer based on their UGT1A1 genotype; however, results of our preliminary modeling of prevalence, acceptance, and effectiveness indicate that reducing the dose would need to be highly effective to have benefits outweigh harms. An alternative is to increase irinotecan dose among wild-type individuals to improve tumor response with minimal increases in adverse drug events. Given the large number of colorectal cancer cases diagnosed each year, a randomized controlled trial of the effects of irinotecan dose modifications in patients with colorectal cancer based on their UGT1A1 genotype is feasible and could clarify the tradeoffs between possible reductions in severe neutropenia and improved tumor response and/or survival in patients with various UGT1A1 genotypes.
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PMID:Can UGT1A1 genotyping reduce morbidity and mortality in patients with metastatic colorectal cancer treated with irinotecan? An evidence-based review. 1912 29

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