Actively Recruiting
Refining Tamoxifen Dose for Premenopausal Breast Cancer Risk Reduction (RENAISSANCE): A Phase II Single Arm Trial
Led by National Cancer Institute (NCI) · Updated on 2026-05-13
200
Participants Needed
11
Research Sites
26 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are evaluating different doses of tamoxifen, a selective estrogen receptor modulator, to reduce breast density in premenopausal women at higher risk for breast cancer. This phase II trial aims to see if increasing tamoxifen doses in women who do not initially respond can improve breast density reduction. The study also explores how tamoxifen levels, biomarkers, genetics, and symptoms relate to treatment response. Participants start by taking tamoxifen 5 mg daily for 6 months. If their breast density reduces by at least 10%, they continue this dose for 12 more months. If not, the dose is increased to 10 mg daily for 6 months, with further assessment. Those still not responding may opt to increase to 20 mg daily for 6 months. Mammograms, blood tests, and optional biopsies are done at screening and during the study. During the trial, participants complete questionnaires about symptoms and adherence. Researchers measure breast density changes at 6, 12, and 18 months, along with blood levels of tamoxifen metabolites and related biomarkers. After completing treatment, participants have a follow-up visit 4 weeks later. The study monitors safety and evaluates how well participants tolerate and follow their tamoxifen dose over time.
CONDITIONS
Brief Title
Finding the Best Tamoxifen Dose for Breast Cancer Risk Reduction in Premenopausal Women, RENAISSANCE Trial
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Premenopausal women defined by either age under 50 with regular menstruation, hormonal contraception use with at least one ovary, or hormone levels indicating premenopausal status
- History of unilateral estrogen receptor positive ductal carcinoma in situ treated locally at least 1 month prior or recent/prior lobular carcinoma in situ or epithelial atypia
- Eligible for preventive medication based on a five-year risk of 1.7% or greater by validated risk models
- Tamoxifen-eligible by ASCO guidelines with specified risk increases
- History of mantle radiotherapy or moderate penetrance germline pathogenic variant
- Age between 18 and 55 years
- ECOG performance status 0 to 2 (Karnofsky score 60% or higher)
- Controlled HIV, hepatitis B, hepatitis C, or herpes simplex virus infections under specified conditions
- Hormonal contraceptive users maintaining the same preparation during the trial
- Agree to use contraception if of childbearing potential
- Ability to understand and sign informed consent
- Breast Imaging Reporting and Data System (BIRADS) 1 or 2, or cleared diagnostic imaging if BIRADS 0
- Factor V Leiden carriers without prior blood clots with physician approval
You will not qualify if you...
- BIRADS breast density category A on most recent mammogram
- Use of selective estrogen receptor modulators within past 5 years except under specific limited conditions
- History of invasive breast cancer
- Prior bilateral mastectomy or breast augmentation; some breast surgeries allowed if over 1 year prior
- Inability to image larger breast in a single mammographic view
- Current use of strong CYP3A4 inducers or CYP2D6 inhibitors unless discontinued
- Current use of Warfarin
- Planning pregnancy within 20 months
- History of thromboembolism, pulmonary embolism, thrombotic stroke, arterial thrombosis, or deep vein thrombosis (except superficial thrombophlebitis)
- History of uterine cancer or atypical uterine hyperplasia with uterus intact
- Receiving other investigational agents
- Allergic reactions to tamoxifen or similar compounds
- Uncontrolled illness or psychiatric/social issues limiting compliance
- Pregnant or breastfeeding women
- Known gene mutations linked to increased breast cancer risk such as BRCA1/2, CDH1, PALB2, PTEN, STK11, or P53
- Current use of sex hormones unless part of oral contraception
- Prior invasive cancer unless treated and completed over 5 years ago
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 - Up to 18 months
Participants receive tamoxifen starting at 5mg daily for 6 months. Based on response measured by mammogram, doses may be escalated to 10mg daily for 6 months, and possibly to 20mg daily for 6 months depending on individual response.
Visits at baseline, 6, 12, and 18 months for mammography, blood collection, and symptom questionnaires; optional biopsy at some visits
Duration - 4 weeks
Participants are followed up 4 weeks after completing treatment to monitor safety and outcomes.
1 visit (in-person)
Trial Site Locations
Total: 11 locations
1
University of Arizona Cancer Center - Prevention Research Clinic
Tucson, Arizona, United States, 85719
Actively Recruiting
2
Northwestern University
Chicago, Illinois, United States, 60611
Actively Recruiting
3
University of Illinois College of Medicine - Chicago
Chicago, Illinois, United States, 60612
Actively Recruiting
4
University of Kansas Cancer Center
Kansas City, Kansas, United States, 66160
Actively Recruiting
5
Brigham and Women's Hospital
Boston, Massachusetts, United States, 02115
Actively Recruiting
6
Dana-Farber Cancer Institute
Boston, Massachusetts, United States, 02215
Actively Recruiting
7
University of Michigan Rogel Cancer Center
Ann Arbor, Michigan, United States, 48109
Actively Recruiting
8
Washington University School of Medicine
St Louis, Missouri, United States, 63110
Actively Recruiting
9
Case Western Reserve University
Cleveland, Ohio, United States, 44106
Actively Recruiting
10
Medical University of South Carolina
Charleston, South Carolina, United States, 29425
Actively Recruiting
11
M D Anderson Cancer Center
Houston, Texas, United States, 77030
Actively Recruiting
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NA
Model
SINGLE_GROUP
Primary Purpose
PREVENTION
Number of Arms
1
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