These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Relationship of drug metabolizing enzyme genotype to plasma levels as well as myelotoxicity of cyclophosphamide in breast cancer patients.
    Author: Afsar NA, Ufer M, Haenisch S, Remmler C, Mateen A, Usman A, Ahmed KZ, Ahmad HR, Cascorbi I.
    Journal: Eur J Clin Pharmacol; 2012 Apr; 68(4):389-95. PubMed ID: 22012257.
    Abstract:
    PURPOSE: The cytotoxic drug cyclophosphamide (CP) is bioactivated into 4-hydroxy-cyclophosphamide (4-OH-CP) through cytochrome P450 enzymes and cleared through aldehyde dehydrogenase and glutathione S-transferase. This prospective study analyzes the influence of drug metabolizing enzyme genotype on (1) plasma 4-OH-CP:CP ratio and (2) myelotoxicity in breast cancer patients on 500 mg/m(2) cyclophosphamide. METHODS: Sixty-eight female breast cancer patients on FAC (fluorouracil, adriamycin, cyclophosphamide) were included. Genotyping of cytochrome P450 enzymes CYP2B6, CYP2C9, CYP2C19, CYP3A5, aldehyde dehydrogenase (ALDH3A1), and glutathione S-transferase (GSTA1) was done either through RFLP or pyrosequencing. Plasma CP and 4-OH-CP were measured immediately and 1 and 2 h after the end of infusion through LC-MS. The leukocyte count was determined on day 10 and 20 after chemotherapy. RESULTS: At CP dose of 500 mg/m(2), the 4-OH-CP:CP ratio was negatively affected by CYP2C19*2 genotype (p = 0.039) showing a gene-dose effect. Moreover ALDH3A1*2 genotype increased 4-OH-CP:CP ratio (p = 0.037). These effects did not remain significant in a univariate analysis of variance including all genotypes. GSTA1*B carriers were at increased risk of severe leucopenia (OR 6.94; 95% CI 1.75-27.6, p = 0.006). CONCLUSION: The myelotoxicity in patients receiving FAC is related to the activity of the phase-II enzyme GSTA1 but is independent of the formation of 4-OH-CP.
    [Abstract] [Full Text] [Related] [New Search]