Trial reportBreast cancer research and treatment2020
Influence of green tea consumption on endoxifen steady-state concentration in breast cancer patients treated with tamoxifen.
Trial report in Breast cancer research and treatment, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 11 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
11 citing papers in PubMed, 1 synthesis or guideline pooled it, 22 citations in OpenAlex.
- Impact of Dietary Supplements on Clinical Outcomes and Quality of Life in Patients with Breast Cancer: A Systematic Review.Nutrients · 2025Pooled it
- Polyphenol‑based interventions in breast cancer: Signaling pathways, molecular mechanisms and translational therapeutic strategies (Review).Oncology reports · 2026Review
- Catechins and Human Health: Breakthroughs from Clinical Trials.Molecules (Basel, Switzerland) · 2025Review
- Current Evidence on the Impact of Diet, Food, and Supplement Intake on Breast Cancer Health Outcomes in Patients Undergoing Endocrine Therapy.Nutrients · 2025Review
- Pharmacodynamics and safety in relation to dose and response of plant flavonoids in treatment of cancers.Inflammopharmacology · 2025Review
- Alzheimer's Disease and Green Tea: Epigallocatechin-3-Gallate as a Modulator of Inflammation and Oxidative Stress.Antioxidants (Basel, Switzerland) · 2023Review
- Interactions between natural products and cancer treatments: underlying mechanisms and clinical importance.Cancer chemotherapy and pharmacology · 2023Review
- Evaluation of Concomitant Use of Anticancer Drugs and Herbal Products: From Interactions to Synergic Activity.Cancers · 2022Article
- A Review of the Pharmacological Potential ofCells · 2022Review
- ClinicalCancers · 2021Review
- Exploring Herbal Medicine Use during Palliative Cancer Care: The Integrative Physician as a Facilitator of Pharmacist-Patient-Oncologist Communication.Pharmaceuticals (Basel, Switzerland) · 2020Review
Corrections and comments
- Erratum issued
Authors and funding
16 authors at 6 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundMany 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.
methodsIn 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 (AUC
resultsNo difference was found in geometric mean endoxifen AUC
conclusionsThis 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.
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