Publications by authors named "Sanchez-Spitman A"
Article Synopsis
- - Tamoxifen is commonly used in breast cancer treatment, but how effective it is can vary significantly among patients, primarily due to differing levels of its active metabolite, endoxifen.
- - A genome-wide association study (GWAS) involving 608 women aimed to find genetic factors that influence endoxifen levels and patient survival outcomes, revealing multiple significant genetic variants.
- - The study found that certain genetic variants on chromosome 22, including those linked to the CYP2D6 gene, are strongly associated with both endoxifen concentration and relapse-free survival in breast cancer patients on tamoxifen.
Background: We aimed to study the pharmacokinetics and -dynamics of tamoxifen in older women with non-metastatic breast cancer.
Methods: Data for this analysis were derived from the CYPTAM study (NTR1509) database. Patients were stratified by age (age groups < 65 and 65 and older).
CYP2C19*2 and CYP2C19*17 might influence tamoxifen metabolism and clinical outcome. Our aim was to investigate the effect of CYP2C19 genotypes on tamoxifen concentrations and metabolic ratios (MRs) and breast cancer recurrence in a large cohort of Caucasian women. Genetic variants (CYP2D6 and CYP2C19 genotypes), tamoxifen and metabolites concentrations, baseline characteristics, and breast cancer recurrence from the CYPTAM study (NTR1509) were used.
View Article and Find Full Text PDFPurpose: Tamoxifen is part of endocrine therapy in breast cancer treatment. Studies have indicated the use of endoxifen concentrations, tamoxifen active metabolite, to guide tamoxifen efficacy. Three endoxifen thresholds have been suggested (5.
View Article and Find Full Text PDFClinical pharmacokinetics and pharmacogenetics of tamoxifen and endoxifen.
Expert Rev Clin Pharmacol
June 2019
: Tamoxifen dominates the anti-estrogenic therapy in the early and metastatic breast cancer setting. Tamoxifen has a complex metabolism, being mainly metabolized by CYP2D6 into its 30-100 times more potent metabolite, endoxifen. Recently, a phase I study in which endoxifen as an orally z-endoxifen hydrochloride has been successfully evaluated.
View Article and Find Full Text PDFPurpose: Tamoxifen is widely prescribed as adjuvant therapy in patients with early-stage breast cancer. It has been postulated that concentrations of endoxifen, the active metabolite of tamoxifen, are a better predictor of tamoxifen efficacy than CYP2D6 genotypes. Although in a retrospective study, an endoxifen threshold of 5.
View Article and Find Full Text PDFPurpose: Tamoxifen has a wide inter-variability. Recently, two SNPs in the 3'-untranslated region (UTR) of the SULT1A1 gene, rs6839 and rs1042157, have been associated with decreased SULT1A1 activity. The aim of this study is to investigate the role of the rs6839 and rs1042157 on tamoxifen metabolism and relapse-free survival (RFS) in women diagnosed with early-breast cancer receiving tamoxifen.
View Article and Find Full Text PDFEffect of CYP3A4*22, CYP3A5*3, and CYP3A combined genotypes on tamoxifen metabolism.
Eur J Clin Pharmacol
December 2017
Background: Tamoxifen is one of the cornerstones of endocrine therapy for breast cancer. Recently, the decreased activity CYP3A4*22 allele and the loss of function CYP3A5*3 allele have been described as potential factors that could help to explain the inter-patient variability in tamoxifen metabolism. The aim of this study is to investigate the effect of CYP3A4*22, CYP3A5*3, and CYP3A combined genotypes on tamoxifen metabolism.
View Article and Find Full Text PDFAim: CYP2D6*2 is considered fully active, but it has been suggested that it only happens in the presence of rs5758550. This study aims to elucidate the impact of this enhancer.
Materials & Methods: DNA and blood samples from women enrolled in the CYPTAM study (NTR1509) were analyzed.