Exercise program to reduce breast cancer risk in women with dense breasts

Resistance and Aerobic Exercise for Prevention in Women With Dense Breasts (REP-D)

Not applicable Interventional Dana-Farber Cancer Institute · NCT06322888

This study is testing if an exercise program can help lower the risk of breast cancer in women with dense breasts.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment46 (estimated)
Ages18 Years to 59 Years
SexFemale
SponsorDana-Farber Cancer Institute Academic / other
Locations2 sites (Boston, Massachusetts and 1 other locations)
Trial IDNCT06322888 on ClinicalTrials.gov

What this trial studies

This study aims to investigate how an exercise program may lower the risk of breast cancer in women with dense breast tissue. Participants will be randomly assigned to either an exercise training group or a waitlist control group. The study will involve assessments such as breast biopsies, physical activity evaluations, aerobic and strength testing, blood draws, and questionnaires. The duration of participation in the study is up to 16 weeks, with a total of 46 women expected to enroll.

Who should consider this trial

Good fit: Ideal candidates are women aged 18-59 with heterogeneously dense or extremely dense breast tissue who are physically inactive.

Not a fit: Patients with a prior history of breast cancer or those who are physically unable to walk 2 blocks may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into how exercise may help reduce breast cancer risk in women with dense breast tissue.

How similar studies have performed: While the approach of using exercise to mitigate breast cancer risk is being explored, this specific study's focus on women with dense breasts is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
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 this trial is running

Boston, Massachusetts and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Breast CancerBreast Cancer FemaleBreast Cancer RiskDense breast tissueDense breasts
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.