Actively Recruiting
Phase 2 Study of Low Dose Tamoxifen With or Without High Dose Omega-3 Fatty Acids in Overweight Postmenopausal Women at Increased Risk for Breast Cancer
Led by National Cancer Institute (NCI) · Updated on 2026-05-20
66
Participants Needed
3
Research Sites
52 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are studying the effects of low dose tamoxifen, with or without high dose omega-3 fatty acids, to reduce breast cancer risk in postmenopausal women who are overweight or obese and at increased risk. Tamoxifen blocks estrogen effects in breast tissue and is approved for breast cancer prevention, while omega-3 fatty acids may help reduce fat production and possibly prevent cancer in this group. This phase II trial aims to understand how these treatments affect certain blood markers and breast tissue genes related to cancer risk. Participants are randomly assigned to one of two groups: one group receives tamoxifen once daily by mouth for 180 days, and the other group receives tamoxifen once daily plus omega-3 fatty acids twice daily for the same duration. Both groups may continue treatment up to 60 additional days if needed due to scheduling delays. Participants undergo mammograms before starting, and blood samples and breast tissue samples via fine needle aspiration are collected at screening and during the study. During the trial, researchers monitor changes in serum adiponectin levels and other markers related to insulin function and breast tissue gene expression. Safety and treatment effects are assessed through blood tests, mammograms, and breast tissue analysis. After the treatment period, participants are followed up 21 to 35 days later. The total participation time includes the 6-month treatment and the follow-up visit to evaluate the outcomes and monitor health.
CONDITIONS
Brief Title
Low Dose Tamoxifen With or Without Omega-3 Fatty Acids for Breast Cancer Risk Reduction
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Age 45 to 74 years
- Female and postmenopausal (defined by ovary removal, amenorrhea, or hormone levels)
- Overweight or obese with BMI of 25 kg/m2 or higher
- Increased breast cancer risk by personal history, genetics, breast density, risk models, or family history
- Willing to undergo fasting blood draw and breast tissue sampling
- ECOG performance status 0 to 2 (Karnofsky 60% or higher)
- At least one unaffected untreated breast available for fine needle aspiration
- Recent mammogram within 12 months showing BIRAD 1 or 2 or cleared clinically
- Ability to understand and sign informed consent
You will not qualify if you...
- Bilateral breast implants
- Prior invasive breast or uterine cancer
- Other invasive cancer treatment within 2 years
- Currently breastfeeding or nursing within 12 months
- Diabetes requiring medication
- Prior blood clots or stroke
- Prior gastric bypass surgery
- Chronic liver disease including NASH or cirrhosis
- BRCA1 or TP53 pathogenic mutation
- Current use of anticoagulants or aspirin that cannot be stopped
- Use of levonorgestrel IUD less than 2 years or planned removal
- Current hormone therapy (except vaginal estrogen)
- Prior use of tamoxifen or similar drugs over 2 months or recent use
- High omega-3 supplement use (>1 gram daily) in last 6 months
- Use of immunosuppressive drugs or certain strong enzyme inducers
- Use or planned use of GLP-1 agonists or metformin
- Receiving other investigational agents
- Allergy to tamoxifen or omega-3 fatty acids
- Uncontrolled illness or conditions limiting study compliance
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 180 days, with up to 60 additional days if needed
Participants receive low dose tamoxifen daily, with or without high dose omega-3 fatty acids twice daily, for 180 days. Participants undergo blood sample collection and random periareolar fine needle aspiration during treatment.
Visits for medication dispensing and assessments throughout treatment
Duration - 21 to 35 days
Participants are followed up to assess outcomes after completing treatment.
1 follow-up visit (in-person)
Trial Site Locations
Total: 3 locations
1
University of Kansas Cancer Center
Kansas City, Kansas, United States, 66160
Actively Recruiting
2
University of Michigan Rogel Cancer Center
Ann Arbor, Michigan, United States, 48109
Actively Recruiting
3
Ohio State University Comprehensive Cancer Center
Columbus, Ohio, United States, 43210
Not Yet Recruiting
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
PREVENTION
Number of Arms
2
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