scholarly journals Correction to: Influence of green tea consumption on endoxifen steady-state concentration in breast cancer patients treated with tamoxifen

2020 ◽  
Author(s):  
C. Louwrens Braal ◽  
Koen G. A. M. Hussaarts ◽  
Lieke Seuren ◽  
Esther Oomen‑deHoop ◽  
Peter de Bruijn ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Steady State ◽  
Cancer Patients ◽  
Green Tea ◽  
Tea Consumption ◽  
Breast Cancer Patients ◽  
Steady State Concentration ◽  
State Concentration

scholarly journals 205P Influence of green tea consumption on endoxifen steady-state concentration in breast cancer patients treated with tamoxifen

2020 ◽  
Vol 31 ◽  
pp. S324
Author(s):  
L. Braal ◽  
K.G.A.M. Hussaarts ◽  
L. Seuren ◽  
E. Oomen-de Hoop ◽  
P. de Bruijn ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Steady State ◽  
Cancer Patients ◽  
Green Tea ◽  
Tea Consumption ◽  
Breast Cancer Patients ◽  
Steady State Concentration ◽  
State Concentration

scholarly journals Biological Effects of Green Tea Capsule Supplementation in Pre-Surgery Postmenopausal Breast Cancer Patients

2013 ◽  
Vol 3 ◽  
Author(s):  
Steven S. Yu ◽  
Darcy V. Spicer ◽  
Debra Hawes ◽  
Chiu-Chen Tseng ◽  
Chung S. Yang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Green Tea ◽  
Biological Effects ◽  
Postmenopausal Breast Cancer ◽  
Breast Cancer Patients

scholarly journals Predicting steady‐state endoxifen plasma concentrations in breast cancer patients by CYP2D6 genotyping or phenotyping. Which approach is more reliable?

2020 ◽  
Vol 8 (5) ◽  
Author(s):  
Milena Gusella ◽  
Felice Pasini ◽  
Barbara Corso ◽  
Laura Bertolaso ◽  
Giovanni De Rosa ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Steady State ◽  
Cancer Patients ◽  
Plasma Concentrations ◽  
Breast Cancer Patients

The Steady-State Pharmacokinetics of Tamoxifen and its Metabolites in Breast Cancer Patients

1986 ◽  
Vol 14 (3) ◽  
pp. 162-165 ◽  
Author(s):  
Kari Soininen ◽  
Terttu Kleimola ◽  
Inkeri Elomaa ◽  
Matti Salmo ◽  
Pentti Rissanen
Keyword(s):  
Breast Cancer ◽  
Steady State ◽  
Cancer Patients ◽  
Mammary Cancer ◽  
Dose Interval ◽  
Urine Samples ◽  
Breast Cancer Patients ◽  
Level Curves ◽  
Plasma And Urine Samples ◽  
To Receive

The steady-state pharmacokinetics of tamoxifen and its metabolites was studied in sixteen patients with advanced mammary cancer. Patients were randomized to receive tamoxifen given as Tamofen®, Leiras, or as Nolvadex®, ICI, 20 mg twice daily for 16 weeks in a cross-over study. Plasma and urine samples were analyzed during one dose interval (12 h) after treatment for 8 and 16 weeks. The concentrations of tamoxifen, N-desmethyltamoxifen, N,N-desdimethyltamoxifen, and metabolite Y were determined in plasma and the areas under the plasma level curves were calculated. 4-Hydroxytamoxifen was not found in plasma. In urine samples only tamoxifen and N-desmethyltamoxifen were above the detection limits even though metabolite Y was also analyzed after acid hydrolysis. There were no statistically significant differences in the concentrations of tamoxifen and its metabolites between the two preparations. The results of nonresponders did not differ from those of responders. Liver metastases had no effect on the metabolism of tamoxifen.

Dextromethorphan phenotyping as a test for prediction of tamoxifen (TAM) activation in breast cancer patients receiving adjuvant hormone therapy.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13019-e13019
Author(s):  
Milena Gusella ◽  
Laura Bertolaso ◽  
Felice Pasini ◽  
Yasmina Modena ◽  
Antonio Bononi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Steady State ◽  
Cancer Patients ◽  
Plasma Levels ◽  
Linear Regression Analysis ◽  
Plasma Concentrations ◽  
Breast Cancer Patients ◽  
Active Metabolites ◽  
Adjuvant Hormone Therapy ◽  
State Plasma

e13019 Background: TAM is mainly metabolized by CYP2D6 to form its most active metabolites, 4hydroxy-tamoxifen (4OH-T) and endoxifen (END). Because of its long half-life, steady state is reached after around 4 months of continuous intake. The wide variable inter-patient activity of CYP2D6 might influence drug efficacy. A multi-institutional study in north Italy is evaluating the relationship between END levels and outcome. As a part of it, we investigated the role of dextromethorphan (DM), a probe drug for CYP2D6 enzymatic activity, as a potential phenotyping test for TAM activation. Methods: Twenty-nine breast cancer patients (75% postmenopausal) on adjuvant TAM therapy (20 mg/die) were investigated. They received a single dose (15 mg) of oral DM before starting TAM and their urines were collected over the10 following hours. Simultaneous quantitative determination of DM and its metabolite dextrorphan (DO) was performed in urines to estimate their log transformed metabolic ratio (LMR=logDM/DO). After 4 months a blood sample was collected to characterize TAM exposure at steady state; plasma levels of TAM, END, 4OH-T and the non active END precursor N-desmethyltamoxifen (NDT) were quantified by HPLC. Linear regression analysis and t test were performed for correlating LMR and drug plasma levels. Results: LMR varied between -2.15 and 0.90 (median: -1.37) while steady state plasma levels of END varied between 1.9 and 15.0 ng/ml (median: 4.36) and 4OH-T between 0.9 to 3.1 ng/ml (median:1.72). A significant correlation (r = 0.56; p= 0.0013) was found between LMR and END plasma concentrations. The patients with high LMR (> median value), compared to patients with low LMR, had lower END (3.7 vs 7.5 ng/ml, p=0.0003), lower 4OH-T (1.6 vs 2.1 ng/ml, p=0.04) and, accordingly, higher NDT (291.2 vs 198.2 ng/ml, p=0.025). Conclusions: DM/DO urine ratio obtained before starting therapy correlates with TAM biotransformation activity and can predict steady state active metabolites exposure in individual patients. This phenotyping test is fast, simple and unexpensive and could contribute to the personalization of adjuvant breast cancer treatment. Funded by Regione Veneto.

scholarly journals Influence of green tea consumption on endoxifen steady-state concentration in breast cancer patients treated with tamoxifen

2020 ◽  
Vol 184 (1) ◽  
pp. 107-113 ◽  
Author(s):  
C. Louwrens Braal ◽  
Koen G. A. M. Hussaarts ◽  
Lieke Seuren ◽  
Esther Oomen-de Hoop ◽  
Peter de Bruijn ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Green Tea ◽  
Geometric Mean ◽  
Area Under The Curve ◽  
Pharmacokinetic Interaction ◽  
Severe Toxicity ◽  
Breast Cancer Patients ◽  
Minimum Concentration ◽  
Anti Cancer

Abstract Background Many cancer patients use additional herbs or supplements in combination with their anti-cancer therapy. Green tea—active ingredient epigallocatechin-3-gallate (EGCG)—is one of the most commonly used dietary supplements among breast cancer patients. EGCG may alter the metabolism of tamoxifen. Therefore, the aim of this study was to investigate the influence of green tea supplements on the pharmacokinetics of endoxifen; the most relevant active metabolite of tamoxifen. Methods In this single-center, randomized cross-over trial, effects of green tea capsules on endoxifen levels were evaluated. Patients treated with tamoxifen for at least 3 months were eligible for this study. After inclusion, patients were consecutively treated with tamoxifen monotherapy for 28 days and in combination with green tea supplements (1 g twice daily; containing 300 mg EGCG) for 14 days (or vice versa). Blood samples were collected on the last day of monotherapy or combination therapy. Area under the curve (AUC0–24h), maximum concentration (Cmax) and minimum concentration (Ctrough) were obtained from individual plasma concentration–time curves. Results No difference was found in geometric mean endoxifen AUC0–24h in the period with green tea versus tamoxifen monotherapy (− 0.4%; 95% CI − 8.6 to 8.5%; p = 0.92). Furthermore, no differences in Cmax (− 2.8%; − 10.6 to 5.6%; p = 0.47) nor Ctrough (1.2%; − 7.3 to 10.5%; p = 0.77) were found. Moreover, no severe toxicity was reported during the whole study period. Conclusions This study demonstrated the absence of a pharmacokinetic interaction between green tea supplements and tamoxifen. Therefore, the use of green tea by patients with tamoxifen does not have to be discouraged.

scholarly journals Fully automated and comprehensive MRI-based left-ventricular contractility analysis in post-chemotherapy breast cancer patients

2020 ◽  
Vol 93 (1105) ◽  
pp. 20190289
Author(s):  
Julia Kar ◽  
Michael V. Cohen ◽  
Samuel A. McQuiston ◽  
Maria S. Figarola ◽  
Christopher M. Malozzi
Keyword(s):  
Breast Cancer ◽  
Steady State ◽  
Cancer Patients ◽  
Healthy Subjects ◽  
Longitudinal Strain ◽  
Steady State Free Precession ◽  
Left Ventricular ◽  
Free Precession ◽  
Breast Cancer Patients ◽  
Basal Diameter

Objective: This study investigated the occurrence of cardiotoxicity-related left-ventricular (LV) contractile dysfunction in breast cancer patients following treatment with antineoplastic chemotherapy agents. Methods: A validated and automated MRI-based LV contractility analysis tool consisting of quantization-based boundary detection, unwrapping of image phases and the meshfree Radial Point Interpolation Method was used toward measuring LV chamber quantifications (LVCQ), three-dimensional strains and torsions in patients and healthy subjects. Data were acquired with the Displacement Encoding with Stimulated Echoes (DENSE) sequence on 21 female patients and 21 age-matched healthy females. Estimates of patient LVCQs from DENSE acquisitions were validated in comparison to similar steady-state free precession measurements and their strain results validated via Bland–Altman interobserver agreements. The occurrence of LV abnormalities was investigated via significant differences in contractility measurements (LVCQs, strains and torsions) between patients and healthy subjects. Results: Repeated measures analysis showed similarities between LVCQ measurements from DENSE and steady-state free precession, including cardiac output (4.7 ± 0.4 L, 4.6 ± 0.4 L, p = 0.8), and LV ejection fractions (59±6%, 58±5%, p = 0.2). Differences found between patients and healthy subjects included enlarged basal diameter (5.0 ± 0.5 cm vs 4.4 ± 0.5 cm, p < 0.01), apical torsion (6.0 ± 1.1° vs 9.7 ± 1.4°, p < 0.001) and global longitudinal strain (−0.15 ± 0.02 vs. -0.21 ± 0.04, p < 0.001), but not LV ejection fraction (59±6% vs. 63±6%, p = 0.1). Conclusion: The results from the statistical analysis reveal the possibility of LV abnormalities in the post-chemotherapy patients via enlarged basal diameter and reduced longitudinal strain and torsion, in comparison to healthy subjects. Advances in knowledge: This study shows that subclinical LV abnormalities in post-chemotherapy breast cancer patients can be detected with an automated technique for the comprehensive analysis of contractile parameters.

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