Trial reportClinical pharmacology and therapeutics2011
Plasma letrozole concentrations in postmenopausal women with breast cancer are associated with CYP2A6 genetic variants, body mass index, and age.
Trial report in Clinical pharmacology and therapeutics, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 41 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
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
41 citing papers in PubMed, 1 synthesis or guideline pooled it, 107 citations in OpenAlex.
- Influence of CYP2C9 and CYP2A6 on plasma concentrations of valproic acid: a meta-analysis.European journal of clinical pharmacology · 2020Pooled it
- Genome-wide association study of aromatase inhibitor discontinuation due to musculoskeletal symptoms.Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer · 2022Trial
- Anti-Müllerian hormone and letrozole levels in boys with constitutional delay of growth and puberty treated with letrozole or testosterone.Human reproduction (Oxford, England) · 2020Trial
- Effects ofPharmacogenomics · 2019Trial
- The Effect of Undaria pinnatifida Fucoidan on the Pharmacokinetics of Letrozole and Tamoxifen in Patients With Breast Cancer.Integrative cancer therapies · 2018Trial
- Prospective assessment of patient-reported outcomes and estradiol and drug concentrations in patients experiencing toxicity from adjuvant aromatase inhibitors.Breast cancer research and treatment · 2017Trial
- Effects of exemestane and letrozole therapy on plasma concentrations of estrogens in a randomized trial of postmenopausal women with breast cancer.Breast cancer research and treatment · 2017Trial
- Patient-Reported Outcomes and Early Discontinuation in Aromatase Inhibitor-Treated Postmenopausal Women With Early Stage Breast Cancer.The oncologist · 2016Trial
- Association of Variants in Candidate Genes with Lipid Profiles in Women with Early Breast Cancer on Adjuvant Aromatase Inhibitor Therapy.Clinical cancer research : an official journal of the American Association for Cancer Research · 2016Trial
- Population pharmacogenetic-based pharmacokinetic modeling of efavirenz, 7-hydroxy- and 8-hydroxyefavirenz.Journal of clinical pharmacology · 2014Trial
- Aromatase inhibitor-induced modulation of breast density: clinical and genetic effects.British journal of cancer · 2013Trial
- Effects of aromatase inhibition and androgen activity on serotonin and behavior in male macaques.Behavioral neuroscience · 2013Trial
- Genetic associations with toxicity-related discontinuation of aromatase inhibitor therapy for breast cancer.Breast cancer research and treatment · 2013Trial
- Aromatase inhibitors induce pain-like musculoskeletal symptoms in mice: behavioural, pharmacological and pathophysiological characterization.British journal of pharmacology · 2026Article
- Genetic variations in CYP2A6 predict efficacy of neoadjuvant letrozole concurrent with chemotherapy in locally advanced hormone receptor-positive breast cancer.Annals of medicine · 2025Article
- Extending Investigations of miR-126-5p on the Regulation of CYP2A6, the Major Nicotine-Inactivating Enzyme.Pharmacology research & perspectives · 2025Article
- The Role of Pharmacogenetic-Based Pharmacokinetic Analysis in Precise Breast Cancer Treatment.Pharmaceutics · 2024Review
- Impact of bariatric surgery on oral anticancer drugs: an analysis of real-world data.Cancer chemotherapy and pharmacology · 2024Article
- Optimisation of Solid-Phase Extraction and LC-MS/MS Analysis of Six Breast Cancer Drugs in Patient Plasma Samples.Pharmaceuticals (Basel, Switzerland) · 2023Article
- In Vitro microRNA Expression Profile Alterations under CDK4/6 Therapy in Breast Cancer.Biomedicines · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
13 authors at 4 institutions in 2 countries.
Funding
Abstract
The associations between plasma letrozole concentrations and CYP2A6 and CYP3A5 genetic variants were tested in the Exemestane and Letrozole Pharmacogenomics (ELPH) trial. ELPH is a multicenter, open-label prospective clinical trial in women randomly assigned (n≈250 in each arm) to receive 2 years of treatment with either oral letrozole (2.5 mg/day) or oral exemestane (25 mg/day). CYP2A6 and CYP3A showed effects on letrozole metabolism in vitro. DNA samples were genotyped for variants in the CYP2A6 and CYP3A5 genes. Plasma letrozole concentrations showed high interpatient variability (>10-fold) and were associated significantly with CYP2A6 genotypes (P<0.0001), body mass index (BMI) (P<0.0001), and age (P=0.0035). However, CYP3A5 genotypes showed no association with plasma letrozole concentrations. These data suggest that CYP2A6 is the principal clearance mechanism for letrozole in vivo. CYP2A6 metabolic status, along with BMI and age, may serve as a biomarker of the efficacy of letrozole treatment or a predictor of adverse effects.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.