Early heart and brain effects of hormone therapy in breast cancer
Looks at heart and brain health in women starting aromatase inhibitors.
Key facts
- Who runs it
- University of Toronto
- Where
- Toronto, CanadaSee the site
- Trial code
- Registry title
- Short-term Impacts of Endocrine Therapy on Cardiovascular and Brain Health Outcomes in Breast Cancer
- Status
- Recruiting
- People taking part
- 40 people, planned
- Started
- 6 Jun 2025
- Expected to end
- 30 Dec 2026
- Type of study
- Observational, 2 groups
- Treatments tested
- N/A (Usual Care)
- Record updated
- 1 October 2025
Who can take part
AI summary
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for post-menopausal women who are about to start an aromatase inhibitor for the first time for early breast cancer. It also needs post-menopausal women without breast cancer as a comparison group.
- Sex
- Women only (biologically female)
- Disease stage
- Stage I, II or III breast cancer that is hormone receptor positive (ER+/PR+) and HER negative, with surgery or radiation already done. A comparison group has no breast cancer.
- Earlier treatment
- Women with breast cancer must be confirmed to start aromatase inhibitor therapy for the first time in the next 2-3 months. They must have had surgery or radiation. If using hormone replacement therapy, at most 3 years of use and none in the last 6 months.
- Biomarker or test result
- Hormone receptor positive (ER+/PR+) and HER negative breast cancer.
Main reasons for not taking part
- Earlier tamoxifen treatment before or around menopause
- Major signs or symptoms of heart disease, diabetes or kidney disease
- Conditions that make a maximal exercise test unsafe, including a cancer other than skin cancer
- Cannot give informed consent or communicate in English
- Mobility limits for exercise testing, or extreme claustrophobia
The registry criteria, word for word
Show all 18 criteriaShow less
Who can take part
- Case group:
- Biologically female
- Post-menopausal with natural (no bilateral oophorectomy) amenorrhea for at least 1 year
- If using hormone replacement therapy, limit of a maximum of 3 years of treatment but not within the last 6 months
- Diagnosis of stage I, II, or III breast cancer
- Hormone receptor positive breast cancer
- HER negative (ER+/PR+/HER-) breast cancer
- Confirmed to start aromatase inhibitor therapy for the first time in next 2-3 months
- Received surgery/radiation therapies; Control group:
- Biologically female
- Post-menopausal with natural (no bilateral oophorectomy) amenorrhea for at least 1 year
- If using hormone replacement therapy, limit of a maximum of 3 years of treatment but not within the last 6 months
Who cannot take part
- Previous treatment using tamoxifen endocrine therapy in a pre-or peri-menopausal setting
- Major signs or symptoms of cardiovascular diseases, diabetes, or renal disease (taken from the American College of Sports Medicine's Guidelines for Exercise Testing and Prescription 11th edition Table 2.1: pain or discomfort in the chest, neck, jaw, arms with rest or exercise, shortness of breath at rest or with mild exertion, dizziness or syncope, loss of balance or passing out, ankle edema, palpitations or tachycardia, intermittent claudication, known heart murmur, unusual fatigue with usual activities.)
- American Heart Association's absolute or relative contraindications for symptom-limited maximal exercise testing (myocardial infarction, aortic or coronary artery stenosis, heart failure, pulmonary embolism or deep vein thrombosis, inflammation of the heart (myocarditis, pericarditis, and/or endocarditis), uncontrolled cardiac arrythmia, advanced or complete electrical heart block, stroke or transient ischemia attack, blood pressure >200mmHg/100mmHg, a cancer diagnosis other than skin cancer)
- Unable to provide informed consent or communicate in English
- Mobility limitations to exercise testing (i.e., wheelchair, walker use, limp impeding walking)
- Extreme claustrophobia
Where in Canada
- University of TorontoToronto, CanadaContact: Amy A. Kirkham, PhDTaking people
About the trial
What the trial wants to find out
Aromatase inhibitors are the most used endocrine therapy for hormone-positive breast cancer. While there is a clear linear relationship between the duration of aromatase inhibitor use and the cumulative incidence of cardiovascular events and mortality, the underlying mechanisms contributing to this risk remain unknown. This study will characterize the short-term effects of aromatase inhibitor therapy on established and novel health indices for cardiovascular diseases in breast cancer patients.
Read full original descriptionShow less
Using a longitudinal case-control design this study will assess the effects of short-term (first 6 months) aromatase inhibitor use in breast cancer patients compared to age- and BMI-matched controls, aiming to determine the cardiovascular, metabolic, and behavioural health impacts of endocrine treatment during this early period. Specifically, our objectives are as follows:
1. To examine the effects of aromatase inhibitor therapy on early risk indicators for cardiovascular disease in the peripheral vasculature and heart, including blood biomarkers (lipids), blood pressure, aortic and peripheral stiffness, carotid artery stiffness and intima media thickness, endothelial function, and left ventricular ejection fraction, longitudinal strain, volumes, and mass, including the responsiveness of the cardiovascular system to an oral glucose tolerance test, in breast cancer survivors compared to controls. 2. To examine the effects of aromatase inhibitor therapy on factors related to cerebrovascular health, autonomic regulation, and cognitive function, including BDNF, heart rate variability, cerebrovascular function in response to a supine-sit-stand maneuver and squatting challenge, and a core battery of cognitive function tests, in breast cancer survivors compared to controls. 3. To examine the effects of aromatase inhibitor therapy on body composition and bone mineral density, along with assessments of glycemic regulation in response to an oral glucose tolerance test and in 24h periods of free-living (continuous glucose monitoring), in breast cancer survivors compared to controls. 4. To examine the effects of aromatase inhibitor therapy on lifestyle factors (behavioural), including diet, physical activity (including cardiorespiratory fitness), sleep, stress, and quality of life, in breast cancer survivors compared to controls.
The investigators hypothesize that cardiovascular and metabolic health outcomes will be similar between breast cancer survivors and controls at baseline but will deteriorate relative to controls within the first 6 months of aromatase inhibitor therapy.
The 2 groups in the trial
- Breast Cancer Patients Receiving Aromatase Inhibitor
Breast Cancer patients using aromatase inhibitors for 6 months
Treatment: N/A (Usual Care)
- Matched Non-Cancer Controls
Arm Description: A woman without a history of cancer will be recruited to match each patient with breast cancer on age and BMI (within 3 years and 3 kg/m2, whenever possible)
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorData and sources
- Registry record
- Listed on ClinicalTrials.gov.
- Official title
- Beyond Cardiotoxicity: Characterizing the Short-term Cardiovascular Side Effects of Breast Cancer Endocrine Treatment
- Plain-language title
- Early heart and brain effects of hormone therapy in breast cancerGenerated from the registry record. The registry title is the official one.
- AI summary
- From the trial's eligibility criteria. Read by machine on 12 November 2026.
- Record updated
- 1 October 2025