Exercise and diet to lower heart and metabolic risk in breast cancer survivors

Multiple Risk Factor Intervention Trial In Breast Cancer Survivors

This project will test whether a 6-month program of Health Canada–based exercise, with or without a healthy-eating counseling program, helps reduce cardiometabolic risk and improve body composition in postmenopausal women who survived early-stage breast cancer and have overweight.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 45 (estimated)
• Sex: Female
• Sponsor: University of Toronto (Academic / other)
• Drugs / interventions: chemotherapy, radiation
• Locations: 1 site (Toronto, Ontario)
• Trial ID: NCT06454864 on ClinicalTrials.gov

What this trial studies

In a three-arm randomized trial, participants will be assigned for six months to (1) exercise following Health Canada guidelines, (2) the same exercise plus counseling to follow Canada's Dietary Guidelines to improve diet quality, or (3) a stretching control group. Outcome measures include cardiometabolic health markers (including insulin resistance and the Matsuda index), body composition, and measures of skeletal muscle adaptation to exercise and diet. The study enrolls postmenopausal, biologically female survivors of stage I–III breast cancer with BMI ≥25 kg/m2 who can attend weekly sessions at the University of Toronto. Investigators hypothesize that exercise will improve cardiometabolic and body composition outcomes and that adding a diet-quality intervention will provide additional benefit and relate to muscle adaptation capacity.

Who should consider this trial

Good fit: Ideal candidates are postmenopausal biological females previously diagnosed with stage I–III breast cancer, BMI ≥25, not currently on chemotherapy or tamoxifen, and able to attend weekly visits at the University of Toronto for 24 weeks.

Not a fit: Patients with metastatic disease, recent or active chemotherapy, active cardiovascular disease or type 2 diabetes, current tamoxifen use, or those unable to participate in regular exercise or weekly visits are unlikely to benefit from this program.

Why it matters

Potential benefit: If successful, participants could see improved blood sugar control, lower cardiovascular risk markers, and healthier body composition that may reduce long-term cardiometabolic disease risk.

How similar studies have performed: Prior research has shown exercise improves cardiometabolic outcomes in cancer survivors, but there is limited direct evidence about the added value of a structured diet-quality program combined with exercise in this specific population.

Eligibility criteria

Inclusion Criteria:

* Biologically female
* Diagnosis of stage I, II, or III breast cancer, post-menopausal at the time of diagnosis (haven't had a menstrual cycle within 12 months or greater)
* Receipt of aromatase inhibitors for 12 months or more in the past, but do not have to be currently on aromatase inhibitors.
* Willing and able to complete all study assessments
* BMI ≥ 25 kg/m2
* Able to commit to come to the University once per week for 24 weeks.

Exclusion Criteria:

* Received chemotherapy within the past 11 months
* Diagnosed with metastatic cancer
* Currently taking tamoxifen
* Currently receiving chemotherapy, targeted therapy or radiation treatment
* Distant recurrence or diagnosis of metastatic cancer since early-stage breast cancer diagnosis
* Diagnosed cardiovascular diseases, type 2 diabetes, non-alcoholic fatty liver disease, uncontrolled thyroid condition, or respiratory disease (e.g., COPD or severe or uncontrolled asthma).
* 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 arrhythmia, 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
* Pregnant or breast-feeding currently or in the past 3 months
* Mobility limitations to aerobic exercise (i.e., wheelchair, walker use, limp impeding walking)
* Smoking cigarettes or marijuana within the past 3 months
* Taking exogenous hormones in any format currently or in the past 3 months
* Contraindications to research MRI (e.g., pacemaker, magnetic implants)
* BMI exceeding 40 kg/m2
* Extreme claustrophobia
* Self-report \>30 min/week of moderate-to-vigorous intensity aerobic physical activity
* Following a diet that largely restricts entire food groups or time of eating (e.g., vegan, ketogenic, carnivore, one meal a day) in last 3 months
* Experienced significant weight loss (i.e., \>5 kg) in past 3 months
* Currently taking weight loss medications
* Diagnosed history of an eating disorder or self-report of potential undiagnosed eating disorder
* Plans to be away/unavailable for a substantial period of the intervention overall (i.e., \>4 weeks throughout the 6 months or \>2 weeks within the first 12 weeks of the intervention).
* Allergies to local anesthetics

Where this trial is running

Toronto, Ontario

• University of Toronto — Toronto, Ontario, Canada (Recruiting)

Study contacts

• Principal investigator: Amy A Kirkham, PhD — University of Toronto
• Study coordinator: Amy A Kirkham, PhD

Conditions Metabolic Disturbance; Sedentary Behavior; Breast Cancer Female