NCT06322888 · Dana-Farber Cancer Institute
Resistance and Aerobic Exercise for Prevention in Women With Dense Breasts (REP-D)
What this study is about
The goal of this study is to learn more about how exercise might lower the risk of developing breast cancer in women with dense breast tissue by studying changes that occur in breast tissue and blood as a result of participating in an exercise program.
View original scientific description
The goal of this study is to learn more about how exercise might lower the risk of developing breast cancer in women with dense breast tissue by studying changes that occur in breast tissue and blood as a result of participating in an exercise program.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Women aged 18-59
- Heterogeneously dense/extremely dense (BIRADS 3 or 4) breast tissue on mammogram within the past 12 months
- Physically inactive; engaging in \<60 minutes of moderate or vigorous intensity exercise per week, as assessed by Godin Leisure Time screener
- Not pregnant or breastfeeding
- English speaking and able to read English. Investigators are only enrolling English-speaking participants to this study at this time due to the fact that investigators currently only have English-speaking exercise trainers with the proper qualifications to conduct the exercise training
- Written informed consent prior to any study-related procedures
Exclusion criteria
- Self-reported inability to walk 2 blocks (at any pace)
- Prior history of breast cancer; prior DCIS is allowable as long as participant is not taking endocrine therapy and has at least 1 breast that has not been irradiated
- On oral or implantable hormonal contraceptives, postmenopausal hormone replacement therapy, a selective estrogen receptor modulator or an aromatase inhibitor; Mirena or other IUD is acceptable
- Consistent strength training in the past 3 months
- Use of weightloss drugs
- Cardiovascular, respiratory or musculoskeletal disease or joint problems that preclude moderate exercise. Examples would include unstable angina, recent myocardial infarction, oxygen-dependent pulmonary disease, and osteoarthritis requiring imminent joint replacement. Moderate arthritis that does not preclude physical activity is not a reason for ineligibility
- Psychiatric disorders or conditions that would preclude participation in the study intervention (e.g. untreated major depression or psychosis, substance abuse, severe personality disorder)
Where
- Boston, Massachusetts
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Nov 21, 2025 · Source of record for eligibility and locations