The role of UGT1A1*28 polymorphism in the pharmacodynamics and pharmacokinetics of irinotecan in patients with metastatic colorectal cancer.
J Clin Oncol
; 24(19): 3061-8, 2006 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-16809730
ABSTRACT
PURPOSE:
UGT1A1*28 polymorphism has been associated with decreased glucuronidation of SN38, the active metabolite of irinotecan. This could increase toxicity with this agent. PATIENTS ANDMETHODS:
In a prospective study, 250 metastatic colorectal cancer patients were treated with irinotecan, fluorouracil, and leucovorin as first-line treatment. UGT1A1*28 polymorphism was investigated with respect to the distribution of hematologic and nonhematologic toxicity, objective response rate, and survival. Pharmacokinetics was investigated in a subgroup of patients (71 of 250) who had been analyzed with respect to toxicity and efficacy.RESULTS:
UGT1A1*28 polymorphism was associated with a higher risk of grade 3 to 4 hematologic toxicity (odds ratio [OR], 8.63; 95% CI, 1.31 to 56.55), which was only relevant for the first cycle, and was not seen throughout the whole treatment period for patients with both variant alleles TA7/TA7 compared with wild-type TA6/TA6. The response rate was also higher in TA7/TA7 patients (OR, 0.32; 95% CI, 0.12 to 0.86) compared with TA6/TA6. A nonsignificant survival advantage was observed for TA7/TA7 when compared with TA6/TA6 patients (hazard ratio, 0.81; 95% CI, 0.45 to 1.44). Higher response rates were explained by a different pharmacokinetics with higher biliary index [irinotecan area under the curve (AUC)x(SN38 AUC/SN38G AUC)] and lower glucuronidation ratio (SN38G AUC/SN38 AUC) associated with the TA7/TA7 genotype and a higher response rate, indicating that the polymorphism is functionally relevant.CONCLUSION:
The results indicate that UGT1A1*28 polymorphism is of some relevance to toxicity; however, it is less important than discussed in previous smaller trials. In particular, the possibility of a dose reduction for irinotecan in patients with a UGT1A1*28 polymorphism is not supported by the result of this analysis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polimorfismo Genético
/
Camptotecina
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Neoplasias Colorretais
/
Protocolos de Quimioterapia Combinada Antineoplásica
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Glucuronosiltransferase
Tipo de estudo:
Clinical_trials
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
J Clin Oncol
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Itália