ReviewBreast cancer research and treatment2007
The discovery and mechanism of action of letrozole.
Review in Breast cancer research and treatment, 2007. 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 83 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
83 citing papers in PubMed, 1 synthesis or guideline pooled it, 210 citations in OpenAlex.
- Triterpenes in breast cancer: a systematic review of preclinical evidence in rodents.Frontiers in pharmacology · 2025Pooled it
- Efficacy and Safety of Letrozole, Misoprostol and Their Combination in First Trimester Missed Miscarriage:Sultan Qaboos University medical journal · 2026Trial
- Clomiphene citrate plus letrozole versus clomiphene citrate alone for ovulation induction in infertile women with ovulatory dysfunction: a randomized controlled trial.BMC women's health · 2023Trial
- A phase I/II study of preoperative letrozole, everolimus, and carotuximab in stage 2 and 3 hormone receptor-positive and Her2-negative breast cancer.Breast cancer research and treatment · 2023Trial
- Effect of Letrozole on sperm parameters, chromatin status and ROS level in idiopathic Oligo/Astheno/Teratozoospermia.Reproductive biology and endocrinology : RB&E · 2020Trial
- A randomized, double-blind, controlled study of exemestane versus anastrozole for the first-line treatment of postmenopausal Japanese women with hormone-receptor-positive advanced breast cancer.Breast cancer research and treatment · 2013Trial
- Rational design of pyrazole-oxime hybrids as dual-targeting agents for glioma and breast cancer brain metastasis.Naunyn-Schmiedeberg's archives of pharmacology · 2026Article
- RRM2 as a biomarker and therapeutic target in letrozole resistant estrogen receptor positive breast cancer.Scientific reports · 2026Article
- Letrozole-Induced Pneumonitis Complicated by Acute Respiratory Distress Syndrome: A Case Report.Cureus · 2026Article
- The letrozole use in reproductive medicine: Beyond aromatase inhibition - a comprehensive review.Turkish journal of obstetrics and gynecology · 2026Article
- Improving the efficacy and targeting of letrozole for the control of breast cancer: in vitro and in vivo studies.Naunyn-Schmiedeberg's archives of pharmacology · 2026Article
- Porcine Leydig cells: central regulators of boar reproductive development and fertility.Journal of animal science · 2026Review
- Dydrogesterone and Letrozole Combination for the Treatment of Endometriosis: A Mechanism-Based Therapeutic Approach.Obstetrics and gynecology international · 2026Article
- Triazole-based hybrid molecules in anticancer drug discovery: structural classes and mechanistic insights, 2014-2025.Beilstein journal of organic chemistry · 2026Review
- Long-term control for > 9 years with megestrol acetate-letrozole: metastatic endometrioid carcinoma case report.Frontiers in oncology · 2026Article
- From Gynecological Endocrine Disorders to Cardiovascular Risk: Insights from Rat Models.Biomedicines · 2025Review
- Letrozole at the Crossroads of Efficacy and Fetal Safety in Ovulation Induction: A Narrative Review.Biomedicines · 2025Review
- Impact of CYP2A6 genetic polymorphism on letrozole efficacy in Iraqi women with polycystic ovary syndrome.Journal of Taibah University Medical Sciences · 2025Article
- The Cytochrome CYP4 in Breast and Other Cancers.Biology · 2025Review
- Liposomal Nanocarriers to Enhance Skin Delivery of Chemotherapeutics in Cancer Therapy.Bioengineering (Basel, Switzerland) · 2025Review
23 more citing papers are in PubMed but not listed here.
Corrections and comments
- Erratum issued
Authors and funding
1 author at 1 institution in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Because estrogen contributes to the promotion and progression of breast cancer, a greater understanding of the role of estrogen in breast cancer has led to therapeutic strategies targeting estrogen synthesis, the estrogen receptor, and intracellular signaling pathways. The enzyme aromatase catalyses the final step in estrogen biosynthesis and was identified as an attractive target for selective inhibition. Modern third-generation aromatase inhibitors (AIs) effectively block the production of estrogen without exerting effects on other steroidogenic pathways. The discovery of letrozole (Femara) achieved the goal of discovering a highly potent and totally selective AI. Letrozole has greater potency than other AIs, including anastrozole, exemestane, formestane, and aminoglutethimide. Moreover, letrozole produces near complete inhibition of aromatase in peripheral tissues and is associated with greater suppression of estrogen than is achieved with other AIs. The potent anti-tumor effects of letrozole were demonstrated in several animal models. Studies with MCF-7Ca xenografts successfully predicted that letrozole would be clinically superior to the previous gold standard tamoxifen and also indicated that it may be more effective than other AIs. An extensive program of randomized clinical trials has demonstrated the clinical benefits of letrozole across the spectrum of hormone-responsive breast cancer in postmenopausal women.
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.